diff --git a/designer/server/src/lib/dead-letter-queue.js b/designer/server/src/lib/dead-letter-queue.js
index 6cc2123f8..fef767fa2 100644
--- a/designer/server/src/lib/dead-letter-queue.js
+++ b/designer/server/src/lib/dead-letter-queue.js
@@ -57,7 +57,14 @@ export async function getDeadLetterQueueMessages(dlq, token) {
 
   const { body } = await getJsonByType(requestUrl, getHeaders(token))
 
-  return body
+  // Dedupe in case of duplicate messages
+  // Ensure the last occurrence of the same MessageId is used as this will contain the valid ReceiptHandle
+  // (older ReceiptHandles for the same message will not be valid)
+  const uniqueMessages = new Map()
+  for (const message of body.messages) {
+    uniqueMessages.set(message.MessageId, message)
+  }
+  return uniqueMessages.values().toArray()
 }
 
 /**
diff --git a/designer/server/src/lib/dead-letter-queue.test.js b/designer/server/src/lib/dead-letter-queue.test.js
index 27fa7bac0..30d99eccb 100644
--- a/designer/server/src/lib/dead-letter-queue.test.js
+++ b/designer/server/src/lib/dead-letter-queue.test.js
@@ -57,7 +57,7 @@ describe('dead-letter queue lib functions', () => {
         new URL('http://localhost:3002/admin/deadletter/form-submissions/view'),
         expect.anything()
       )
-      expect(res.messages).toEqual(['message1'])
+      expect(res).toEqual(['message1'])
     })
   })
 
diff --git a/designer/server/src/routes/admin/dead-letter-queues.js b/designer/server/src/routes/admin/dead-letter-queues.js
index afbb12212..abf39dd07 100644
--- a/designer/server/src/routes/admin/dead-letter-queues.js
+++ b/designer/server/src/routes/admin/dead-letter-queues.js
@@ -88,7 +88,7 @@ export async function getMessageCounts(token) {
   const radioItems = []
   for (const dlq of Object.values(DeadLetterQueues)) {
     try {
-      const { messages } = await getDeadLetterQueueMessages(dlq, token)
+      const messages = await getDeadLetterQueueMessages(dlq, token)
       const countSuffix = messages.length === 1 ? 'message' : 'messages'
       radioItems.push({
         value: dlq,
@@ -217,7 +217,7 @@ export default [
 
       const navigation = buildAdminNavigation(ADMIN_TOOLS)
 
-      const { messages } = await getDeadLetterQueueMessages(dlq, token)
+      const messages = await getDeadLetterQueueMessages(dlq, token)
 
       const mappedMessages = dlqMessageMapper(messages)
 
diff --git a/designer/server/src/routes/admin/dead-letter-queues.test.js b/designer/server/src/routes/admin/dead-letter-queues.test.js
index 5c9ef611c..0508bbf4d 100644
--- a/designer/server/src/routes/admin/dead-letter-queues.test.js
+++ b/designer/server/src/routes/admin/dead-letter-queues.test.js
@@ -35,12 +35,12 @@ describe('Dead-letter queues routes', () => {
     test('should render form with radio options with counts', async () => {
       jest
         .mocked(getDeadLetterQueueMessages)
-        .mockResolvedValueOnce({ messages: [] })
+        .mockResolvedValueOnce([])
         // @ts-expect-error - invalid response to throw error
         .mockResolvedValueOnce(undefined)
-        .mockResolvedValueOnce({ messages: [{}, {}] })
-        .mockResolvedValueOnce({ messages: [{}, {}, {}] })
-        .mockResolvedValueOnce({ messages: [{}, {}, {}, {}] })
+        .mockResolvedValueOnce([{}, {}])
+        .mockResolvedValueOnce([{}, {}, {}])
+        .mockResolvedValueOnce([{}, {}, {}, {}])
       const options = {
         method: 'get',
         url: '/admin/dead-letter-queues',
@@ -121,15 +121,13 @@ describe('Dead-letter queues routes', () => {
     })
 
     test('should redirect to next screen if valid queue selected and display queue messages', async () => {
-      jest.mocked(getDeadLetterQueueMessages).mockResolvedValue({
-        messages: [
-          {
-            MessageId: 'message-id',
-            Body: '{ "field1": "value1" }',
-            ReceiptHandle: 'rec-handle'
-          }
-        ]
-      })
+      jest.mocked(getDeadLetterQueueMessages).mockResolvedValue([
+        {
+          MessageId: 'message-id',
+          Body: '{ "field1": "value1" }',
+          ReceiptHandle: 'rec-handle'
+        }
+      ])
       const options = {
         method: 'post',
         url: '/admin/dead-letter-queues',
@@ -146,15 +144,13 @@ describe('Dead-letter queues routes', () => {
     })
 
     test('should render form with messages and redrive button', async () => {
-      jest.mocked(getDeadLetterQueueMessages).mockResolvedValue({
-        messages: [
-          {
-            MessageId: 'message-id',
-            Body: '{ "field1": "value1" }',
-            ReceiptHandle: 'rec-handle'
-          }
-        ]
-      })
+      jest.mocked(getDeadLetterQueueMessages).mockResolvedValue([
+        {
+          MessageId: 'message-id',
+          Body: '{ "field1": "value1" }',
+          ReceiptHandle: 'rec-handle'
+        }
+      ])
 
       const options = {
         method: 'get',