diff --git a/app/connectors_service/connectors/es/management_client.py b/app/connectors_service/connectors/es/management_client.py
index 0aa2917f0..75ff8753a 100644
--- a/app/connectors_service/connectors/es/management_client.py
+++ b/app/connectors_service/connectors/es/management_client.py
@@ -189,7 +189,7 @@ async def bulk_insert(self, operations, pipeline):
         )
 
     async def yield_existing_documents_metadata(self, index):
-        """Returns an iterator on the `id` and `_timestamp` fields of all documents in an index.
+        """Returns an iterator on the `_id` and `_timestamp` fields of all documents in an index.
 
         WARNING
 
@@ -203,10 +203,10 @@ async def yield_existing_documents_metadata(self, index):
             return
 
         async for doc in async_scan(
-            client=self.client, index=index, _source=["id", TIMESTAMP_FIELD]
+            client=self.client, index=index, _source=[TIMESTAMP_FIELD]
         ):
             source = doc["_source"]
-            doc_id = source.get("id", doc["_id"])
+            doc_id = doc["_id"]
             timestamp = source.get(TIMESTAMP_FIELD)
 
             yield doc_id, timestamp
diff --git a/app/connectors_service/tests/es/test_management_client.py b/app/connectors_service/tests/es/test_management_client.py
index 18ac77858..c8cbca5f9 100644
--- a/app/connectors_service/tests/es/test_management_client.py
+++ b/app/connectors_service/tests/es/test_management_client.py
@@ -192,6 +192,30 @@ async def test_yield_existing_documents_metadata_when_index_exists(
 
             assert ids == ["1", "2"]
 
+    @pytest.mark.asyncio
+    async def test_yield_existing_documents_metadata_when_source_id_differs_from_id(
+        self, es_management_client, mock_responses
+    ):
+        es_management_client.index_exists = AsyncMock(return_value=True)
+
+        records = [
+            {"_id": "1", "_source": {"id": "a", "_timestamp": str(datetime.now())}},
+            {"_id": "2", "_source": {"id": "b", "_timestamp": str(datetime.now())}},
+        ]
+
+        with mock.patch(
+            "connectors.es.management_client.async_scan",
+            return_value=AsyncIterator(records),
+        ):
+            ids = []
+            async for (
+                doc_id,
+                _,
+            ) in es_management_client.yield_existing_documents_metadata("something"):
+                ids.append(doc_id)
+
+            assert ids == ["1", "2"]
+
     @pytest.mark.asyncio
     async def test_get_connector_secret(self, es_management_client, mock_responses):
         secret_id = "secret-id"
diff --git a/app/connectors_service/tests/test_sink.py b/app/connectors_service/tests/test_sink.py
index 2d5f80449..256f94a14 100644
--- a/app/connectors_service/tests/test_sink.py
+++ b/app/connectors_service/tests/test_sink.py
@@ -766,6 +766,38 @@ async def test_get_docs(
         assert queue_called_with_operations(queue, expected_queue_operations)
 
 
+@mock.patch("connectors.es.management_client.async_scan")
+@mock.patch(
+    "connectors.es.management_client.ESManagementClient.index_exists",
+    return_value=True,
+)
+@pytest.mark.asyncio
+async def test_get_docs_matches_and_deletes_existing_docs_by_es_id(
+    index_exists, async_scan
+):
+    # e.g. an ingest pipeline rewrote `id`, so it no longer matches `_id`
+    async_scan.return_value = AsyncIterator(
+        [
+            {"_id": "1", "_source": {"id": "rewritten-1", "_timestamp": TIMESTAMP}},
+            {"_id": "2", "_source": {"id": "rewritten-2", "_timestamp": TIMESTAMP}},
+        ]
+    )
+    queue = await queue_mock()
+    extractor = await setup_extractor(queue)
+
+    await extractor.run(
+        AsyncIterator([(deepcopy(DOC_ONE), None, "index")]), JobType.FULL
+    )
+
+    assert extractor.counters.get(UPDATES_QUEUED) == 1
+    assert extractor.counters.get(CREATES_QUEUED) == 0
+    assert extractor.counters.get(DELETES_QUEUED) == 1
+    assert queue_called_with_operations(
+        queue,
+        [index_operation(DOC_ONE), delete_operation(DOC_TWO), end_docs_operation()],
+    )
+
+
 def test_log_progress_includes_extraction_counters():
     logger_mock = Mock()
     extractor = Extractor(None, Mock(), INDEX, logger_=logger_mock)