diff --git a/server/src/__tests__/decision-queues-routes.test.ts b/server/src/__tests__/decision-queues-routes.test.ts
index 1c056b771c3..bca0b210f6e 100644
--- a/server/src/__tests__/decision-queues-routes.test.ts
+++ b/server/src/__tests__/decision-queues-routes.test.ts
@@ -224,6 +224,9 @@ describeEmbeddedPostgres("decision queue routes", () => {
       "issue_thread_interaction",
       "review",
     ]);
+    await request(app(agentActor(companyId, agentId)))
+      .delete(`/api/companies/${companyId}/decision-queues/triage/items/approval/${approvalId}`)
+      .expect(404);
 
     await request(app(board))
       .delete(`/api/companies/${companyId}/decision-queues/triage/items/review/${issueId}`)
@@ -236,7 +239,11 @@ describeEmbeddedPostgres("decision queue routes", () => {
     await db.delete(approvals).where(eq(approvals.id, approvalId));
     await request(app(board))
       .delete(`/api/companies/${companyId}/decision-queues/triage/items/approval/${approvalId}`)
-      .expect(404);
+      .expect(200);
+    expect(await db.select().from(decisionQueueItems).where(and(
+      eq(decisionQueueItems.companyId, companyId),
+      eq(decisionQueueItems.sourceKind, "approval"),
+    ))).toHaveLength(0);
   });
 
   it("materializes data-backed starter queues from plan, question, and pull-request signals", async () => {
diff --git a/server/src/services/decision-queues.ts b/server/src/services/decision-queues.ts
index 47398e12128..a0dfd24586b 100644
--- a/server/src/services/decision-queues.ts
+++ b/server/src/services/decision-queues.ts
@@ -539,7 +539,19 @@ export function decisionQueueService(db: Db) {
     }) => {
       const queue = await getQueue(input.companyId, input.key);
       if (!queue) throw notFound("Decision queue not found");
-      await requireSourceRead(db, input.authActor, input.companyId, input.sourceKind, input.sourceId);
+      const sourceReadable = await canReadDecisionSource(
+        db,
+        input.authActor,
+        input.companyId,
+        input.sourceKind,
+        input.sourceId,
+      );
+      // Board operators may clean up an existing sidecar after its source has
+      // disappeared. Agents still need source-level read authority so removal
+      // cannot be used to probe hidden membership.
+      if (!sourceReadable && input.authActor.type !== "board") {
+        throw notFound("Attention source not found");
+      }
       return db.transaction(async (tx) => {
         const txDb = tx as unknown as Db;
         const removed = await txDb.delete(decisionQueueItems).where(and(