diff --git a/components/admin/tabs/storage.js b/components/admin/tabs/storage.js
index 513a7933..184bc066 100644
--- a/components/admin/tabs/storage.js
+++ b/components/admin/tabs/storage.js
@@ -2,7 +2,6 @@
 import { useState } from "react";
 import Link from "next/link";
 import { bytesToSize } from "../../../components/utils";
-import { deleteAwaitingSubmissionsFromBlob } from "../../../actions/services/documentService";
 import { consoleLogger } from "../../../actions/core/logger";
 
 import { formatBlobDates } from "../utils/adminHelper";
@@ -136,20 +135,52 @@ export default function StorageTab({ data, repCompleteCount }) {
                                         {folder.hasTmpFile && (
                                             <>
                                                 <button
-                                                    onClick={() => {
-                                                        confirm(
-                                                            "Do you want to remove this unsubmitted appeal " +
-                                                                folder.folderPath +
-                                                                "?\n"
-                                                        ) &&
-                                                            (deleteCaseItem(
-                                                                c.container,
-                                                                folder.folderPath,
-                                                                setData
-                                                            ),
+                                                    onClick={async () => {
+                                                        if (
+                                                            !confirm(
+                                                                "Do you want to remove this unsubmitted appeal " +
+                                                                    folder.folderPath +
+                                                                    "?\n"
+                                                            )
+                                                        ) {
+                                                            return;
+                                                        }
+
+                                                        try {
+                                                            const response =
+                                                                await fetch(
+                                                                    "/api/admin/deleteblobcase",
+                                                                    {
+                                                                        method: "POST",
+                                                                        headers:
+                                                                            {
+                                                                                "Content-Type":
+                                                                                    "application/json"
+                                                                            },
+                                                                        body: JSON.stringify(
+                                                                            {
+                                                                                container:
+                                                                                    c.container,
+                                                                                casefolderID:
+                                                                                    folder.folderPath
+                                                                            }
+                                                                        )
+                                                                    }
+                                                                );
+
+                                                            if (!response.ok) {
+                                                                throw new Error(
+                                                                    "Unable to delete case"
+                                                                );
+                                                            }
+
                                                             alert(
                                                                 "Temp case Deleted!"
-                                                            ));
+                                                            );
+                                                            window.location.reload();
+                                                        } catch (error) {
+                                                            consoleLogger(error);
+                                                        }
                                                     }}
                                                 >
                                                     Delete this TMP appeal
diff --git a/docs/administrative-authentication.md b/docs/administrative-authentication.md
index 44a941c0..ca380f12 100644
--- a/docs/administrative-authentication.md
+++ b/docs/administrative-authentication.md
@@ -95,20 +95,30 @@ the administrative session and requires a trusted same-origin request. It also
 validates the requested container, case-folder segment, and representation-file
 segment before performing deletion.
 
+Administrative cross-container case deletion uses the dedicated
+`POST /api/admin/deleteblobcase` route. That endpoint independently validates
+the administrative session, requires a trusted same-origin request, and
+validates the requested container and case-folder segment before performing
+deletion. It invokes the same existing `deleteBlobCase(container,
+casefolderID)` operation as the ordinary endpoint. That operation lists and
+deletes blobs in the selected container whose names begin with the supplied
+case-folder prefix; it does not delete the Azure container or broaden deletion
+to unrelated containers.
+
 Administrative representation JSON unlocking uses the dedicated
 `POST /api/admin/editRepJson` route. That endpoint independently validates the
 administrative session, requires a trusted same-origin request, and validates
 the requested container and blob path before removing `repComplete`. The former
 `/api/file/editRepJson` route is retired and no longer performs storage access.
 
-Administrative case deletion was not investigated or remediated as part of
-Stage 3 and remains a separate, unverified security boundary. The other
-administrative API and storage limitations documented above also remain open.
-
 Automated contract verification for the implemented deletion controls has
-passed. Live Azure behaviour, browser-level behaviour, and deployment
-configuration have not been verified by that automated coverage. These changes
-do not establish closure of the overall ITHC finding.
+passed, including ordinary ownership/HMAC rejection, administrative method,
+session, origin and input rejection, zero deletion calls on rejected requests,
+and exact cross-container helper arguments on success. Live Azure behaviour,
+browser-level behaviour, and deployment configuration have not been verified
+by that automated coverage. The other administrative API and storage
+limitations documented above remain open, and these changes do not establish
+closure of the overall ITHC finding.
 
 ## Deployment requirements before production use
 
diff --git a/pages/api/admin/deleteblobcase.js b/pages/api/admin/deleteblobcase.js
new file mode 100644
index 00000000..67f7a741
--- /dev/null
+++ b/pages/api/admin/deleteblobcase.js
@@ -0,0 +1,71 @@
+import { deleteBlobCase } from "../../../actions/azurestorage";
+import {
+    hasTrustedSameOrigin,
+    readAdminSessionCookie,
+    setAdminAuthNoStore,
+    validateAdminSession
+} from "../../../lib/admin/adminAuth";
+import { respondError, respondSuccess } from "../middleware/apiResponse";
+
+const forbidden = (res) =>
+    respondError(res, {
+        status: 403,
+        code: "FORBIDDEN",
+        message: "Request not permitted"
+    });
+
+const isValidContainer = (value) =>
+    typeof value === "string" &&
+    value.length >= 3 &&
+    value.length <= 63 &&
+    /^[a-z0-9](?:[a-z0-9-]*[a-z0-9])?$/.test(value);
+
+const isValidPathSegment = (value) =>
+    typeof value === "string" &&
+    value.length > 0 &&
+    value.length <= 255 &&
+    value === value.trim() &&
+    value !== "." &&
+    value !== ".." &&
+    !/[\\/\u0000-\u001f\u007f]/.test(value);
+
+export default async function handler(req, res) {
+    setAdminAuthNoStore(res);
+    res.setHeader("Allow", "POST");
+
+    if (req.method !== "POST") {
+        return respondError(res, {
+            status: 405,
+            code: "METHOD_NOT_ALLOWED",
+            message: "Method not allowed"
+        });
+    }
+
+    const adminSession = readAdminSessionCookie(req);
+    if (
+        !validateAdminSession(adminSession) ||
+        !hasTrustedSameOrigin(req)
+    ) {
+        return forbidden(res);
+    }
+
+    const { container, casefolderID } = req.body ?? {};
+    if (!isValidContainer(container) || !isValidPathSegment(casefolderID)) {
+        return respondError(res, {
+            status: 400,
+            code: "INVALID_REQUEST",
+            message: "Invalid request"
+        });
+    }
+
+    try {
+        const data = await deleteBlobCase(container, casefolderID);
+        return respondSuccess(res, { data });
+    } catch (_error) {
+        return respondError(res, {
+            status: 400,
+            code: "DELETE_BLOB_CASE_FAILED",
+            message: "Unable to delete blob case"
+        });
+    }
+}
\ No newline at end of file
diff --git a/tests/phase21/file-handler-contract.test.cjs b/tests/phase21/file-handler-contract.test.cjs
index b18ae8a3..b6272595 100644
--- a/tests/phase21/file-handler-contract.test.cjs
+++ b/tests/phase21/file-handler-contract.test.cjs
@@ -573,6 +573,207 @@ test("admin storage caller uses dedicated POST deletion while ordinary caller re
     );
 });
 
+const loadAdminCaseDeletion = (overrides = {}) => {
+    const calls = {
+        noStore: 0,
+        readSession: 0,
+        validateSession: 0,
+        origin: 0,
+        deletion: []
+    };
+    const payload = { deleted: "TMP-CASE-1" };
+    const mod = loadModule("pages/api/admin/deleteblobcase.js", {
+        deleteBlobCase: async (...args) => {
+            calls.deletion.push(args);
+            return payload;
+        },
+        readAdminSessionCookie: () => {
+            calls.readSession += 1;
+            return "admin-token";
+        },
+        validateAdminSession: () => {
+            calls.validateSession += 1;
+            return true;
+        },
+        hasTrustedSameOrigin: () => {
+            calls.origin += 1;
+            return true;
+        },
+        setAdminAuthNoStore: () => {
+            calls.noStore += 1;
+        },
+        respondError: respondErrorMock,
+        respondSuccess: respondSuccessMock,
+        ...overrides
+    });
+
+    return { mod, calls, payload };
+};
+
+const validAdminCaseDeletionRequest = (overrides = {}) => ({
+    method: "POST",
+    headers: {
+        origin: "https://portal.example.test",
+        cookie: "pedw_admin_session=admin-token"
+    },
+    body: {
+        container: "selected-user-container",
+        casefolderID: "TMP-CASE-1"
+    },
+    ...overrides
+});
+
+for (const method of ["GET", "DELETE"]) {
+    test(`admin case deletion rejects ${method} with 405 before authorization or deletion`, async () => {
+        const loaded = loadAdminCaseDeletion();
+        const res = createRes();
+
+        await loaded.mod.default(
+            validAdminCaseDeletionRequest({ method }),
+            res
+        );
+
+        assert.strictEqual(res.state.statusCode, 405);
+        assert.strictEqual(res.state.headers.allow, "POST");
+        assert.strictEqual(res.state.jsonBody.error.code, "METHOD_NOT_ALLOWED");
+        assert.strictEqual(loaded.calls.noStore, 1);
+        assert.strictEqual(loaded.calls.readSession, 0);
+        assert.strictEqual(loaded.calls.deletion.length, 0);
+    });
+}
+
+for (const sessionCase of [
+    { name: "missing", token: null },
+    { name: "invalid", token: "invalid-token" },
+    { name: "expired", token: "expired-token" }
+]) {
+    test(`admin case deletion rejects ${sessionCase.name} administrative session before deletion`, async () => {
+        const loaded = loadAdminCaseDeletion({
+            readAdminSessionCookie: () => sessionCase.token,
+            validateAdminSession: () => false
+        });
+        const res = createRes();
+
+        await loaded.mod.default(validAdminCaseDeletionRequest(), res);
+
+        assert.strictEqual(res.state.statusCode, 403);
+        assert.strictEqual(res.state.jsonBody.error.code, "FORBIDDEN");
+        assert.strictEqual(loaded.calls.origin, 0);
+        assert.strictEqual(loaded.calls.deletion.length, 0);
+    });
+}
+
+for (const originCase of [
+    { name: "missing", headers: { cookie: "pedw_admin_session=admin-token" } },
+    {
+        name: "cross-origin",
+        headers: {
+            origin: "https://attacker.example.test",
+            cookie: "pedw_admin_session=admin-token"
+        }
+    }
+]) {
+    test(`admin case deletion rejects ${originCase.name} Origin before deletion`, async () => {
+        const loaded = loadAdminCaseDeletion({
+            hasTrustedSameOrigin: () => false
+        });
+        const res = createRes();
+
+        await loaded.mod.default(
+            validAdminCaseDeletionRequest({ headers: originCase.headers }),
+            res
+        );
+
+        assert.strictEqual(res.state.statusCode, 403);
+        assert.strictEqual(loaded.calls.deletion.length, 0);
+    });
+}
+
+for (const inputCase of [
+    { name: "missing container", body: { container: undefined } },
+    { name: "malformed container", body: { container: "Invalid_Container" } },
+    { name: "missing case identifier", body: { casefolderID: undefined } },
+    { name: "case identifier path separator", body: { casefolderID: "TMP/CASE-1" } },
+    { name: "case identifier traversal segment", body: { casefolderID: ".." } },
+    { name: "case identifier control character", body: { casefolderID: "TMP\u0000CASE" } }
+]) {
+    test(`admin case deletion rejects ${inputCase.name} without deletion`, async () => {
+        const loaded = loadAdminCaseDeletion();
+        const request = validAdminCaseDeletionRequest();
+        const res = createRes();
+
+        request.body = { ...request.body, ...inputCase.body };
+        Object.keys(request.body).forEach((key) => {
+            if (typeof request.body[key] === "undefined") delete request.body[key];
+        });
+        await loaded.mod.default(request, res);
+
+        assert.strictEqual(res.state.statusCode, 400);
+        assert.strictEqual(res.state.jsonBody.error.code, "INVALID_REQUEST");
+        assert.strictEqual(loaded.calls.deletion.length, 0);
+    });
+}
+
+test("valid administrator can delete a cross-container case prefix with the existing helper", async () => {
+    const loaded = loadAdminCaseDeletion();
+    const request = validAdminCaseDeletionRequest();
+    const res = createRes();
+
+    await loaded.mod.default(request, res);
+
+    assert.strictEqual(res.state.statusCode, 200);
+    assert.deepStrictEqual(loaded.calls.deletion, [
+        [request.body.container, request.body.casefolderID]
+    ]);
+    assert.deepStrictEqual(
+        JSON.parse(JSON.stringify(res.state.jsonBody)),
+        { data: loaded.payload }
+    );
+});
+
+test("admin case deletion dependency failure returns DELETE_BLOB_CASE_FAILED", async () => {
+    const loaded = loadAdminCaseDeletion({
+        deleteBlobCase: async (...args) => {
+            loaded.calls.deletion.push(args);
+            throw new Error("delete case failed");
+        }
+    });
+    const res = createRes();
+
+    await loaded.mod.default(validAdminCaseDeletionRequest(), res);
+
+    assert.strictEqual(res.state.statusCode, 400);
+    assert.strictEqual(
+        res.state.jsonBody.error.code,
+        "DELETE_BLOB_CASE_FAILED"
+    );
+    assert.strictEqual(loaded.calls.deletion.length, 1);
+});
+
+test("admin storage case deletion uses dedicated POST route while ordinary callers remain signed GET", () => {
+    const rootDir = path.resolve(__dirname, "..", "..");
+    const adminSource = fs.readFileSync(
+        path.join(rootDir, "components/admin/tabs/storage.js"),
+        "utf8"
+    );
+    const ordinarySource = fs.readFileSync(
+        path.join(rootDir, "actions/services/documentDirectService.js"),
+        "utf8"
+    );
+
+    assert.match(adminSource, /fetch\(\s*"\/api\/admin\/deleteblobcase"/);
+    assert.match(
+        adminSource,
+        /"\/api\/admin\/deleteblobcase"[\s\S]*method:\s*"POST"[\s\S]*container:\s*c\.container[\s\S]*casefolderID:\s*folder\.folderPath/
+    );
+    assert.match(adminSource, /if \(!response\.ok\)/);
+    assert.doesNotMatch(adminSource, /deleteAwaitingSubmissionsFromBlob/);
+    assert.match(
+        ordinarySource,
+        /buildFileQuery\("\/api\/file\/deleteblobcase"[\s\S]*getSignedFileJson\(queryUrl\)/
+    );
+});
+
 const loadAdminRepJsonEdit = (overrides = {}) => {
     let azureClientConstructions = 0;
     const storageCalls = [];