diff --git a/swh/storage/cassandra/cql.py b/swh/storage/cassandra/cql.py
--- a/swh/storage/cassandra/cql.py
+++ b/swh/storage/cassandra/cql.py
@@ -1126,6 +1126,18 @@
             ),
         )
 
+    @_prepared_statement(
+        "SELECT authority_type, authority_url FROM raw_extrinsic_metadata "
+        "WHERE target = ?"
+    )
+    def raw_extrinsic_metadata_get_authorities(
+        self, target: str, *, statement
+    ) -> Iterable[Tuple[str, str]]:
+        return (
+            (entry["authority_type"], entry["authority_url"])
+            for entry in self._execute_with_retries(statement, [target])
+        )
+
     ##########################
     # 'extid' table
     ##########################
diff --git a/swh/storage/cassandra/storage.py b/swh/storage/cassandra/storage.py
--- a/swh/storage/cassandra/storage.py
+++ b/swh/storage/cassandra/storage.py
@@ -1393,6 +1393,18 @@
 
         return list(results)
 
+    def raw_extrinsic_metadata_get_authorities(
+        self, target: ExtendedSWHID
+    ) -> List[MetadataAuthority]:
+        return [
+            MetadataAuthority(
+                type=MetadataAuthorityType(authority_type), url=authority_url
+            )
+            for (authority_type, authority_url) in set(
+                self._cql_runner.raw_extrinsic_metadata_get_authorities(str(target))
+            )
+        ]
+
     def metadata_fetcher_add(self, fetchers: List[MetadataFetcher]) -> Dict[str, int]:
         self.journal_writer.metadata_fetcher_add(fetchers)
         for fetcher in fetchers:
diff --git a/swh/storage/in_memory.py b/swh/storage/in_memory.py
--- a/swh/storage/in_memory.py
+++ b/swh/storage/in_memory.py
@@ -660,6 +660,12 @@
             if m.authority_type == authority_type and m.authority_url == authority_url
         )
 
+    def raw_extrinsic_metadata_get_authorities(
+        self, target: str
+    ) -> Iterable[Tuple[str, str]]:
+        metadata = self._raw_extrinsic_metadata.get_from_partition_key((target,))
+        return ((m.authority_type, m.authority_url) for m in metadata)
+
     #########################
     # 'extid' table
     #########################
diff --git a/swh/storage/interface.py b/swh/storage/interface.py
--- a/swh/storage/interface.py
+++ b/swh/storage/interface.py
@@ -1220,6 +1220,13 @@
         """
         ...
 
+    @remote_api_endpoint("raw_extrinsic_metadata/get_authorities")
+    def raw_extrinsic_metadata_get_authorities(
+        self, target: ExtendedSWHID
+    ) -> List[MetadataAuthority]:
+        """Returns all authorities that provided metadata on the given object."""
+        ...
+
     @remote_api_endpoint("metadata_fetcher/add")
     def metadata_fetcher_add(self, fetchers: List[MetadataFetcher],) -> Dict[str, int]:
         """Add new metadata fetchers to the storage.
diff --git a/swh/storage/postgresql/db.py b/swh/storage/postgresql/db.py
--- a/swh/storage/postgresql/db.py
+++ b/swh/storage/postgresql/db.py
@@ -1350,6 +1350,21 @@
             [(id_,) for id_ in ids],
         )
 
+    def raw_extrinsic_metadata_get_authorities(self, id: str, cur=None):
+        cur = self._cursor(cur)
+        cur.execute(
+            """
+            SELECT
+                DISTINCT metadata_authority.type, metadata_authority.url
+            FROM raw_extrinsic_metadata
+            INNER JOIN metadata_authority
+                ON (metadata_authority.id=authority_id)
+            WHERE raw_extrinsic_metadata.target = %s
+            """,
+            (id,),
+        )
+        yield from cur
+
     metadata_fetcher_cols = ["name", "version"]
 
     def metadata_fetcher_add(self, name: str, version: str, cur=None) -> None:
diff --git a/swh/storage/postgresql/storage.py b/swh/storage/postgresql/storage.py
--- a/swh/storage/postgresql/storage.py
+++ b/swh/storage/postgresql/storage.py
@@ -1441,6 +1441,20 @@
             for row in db.raw_extrinsic_metadata_get_by_ids(ids)
         ]
 
+    @db_transaction()
+    def raw_extrinsic_metadata_get_authorities(
+        self, target: ExtendedSWHID, db=None, cur=None,
+    ) -> List[MetadataAuthority]:
+        return [
+            MetadataAuthority(
+                type=MetadataAuthorityType(authority_type), url=authority_url
+            )
+            for (
+                authority_type,
+                authority_url,
+            ) in db.raw_extrinsic_metadata_get_authorities(str(target), cur)
+        ]
+
     @timed
     @process_metrics
     @db_transaction()
diff --git a/swh/storage/tests/storage_tests.py b/swh/storage/tests/storage_tests.py
--- a/swh/storage/tests/storage_tests.py
+++ b/swh/storage/tests/storage_tests.py
@@ -4064,6 +4064,55 @@
             )
         ) == {content1_metadata1, content2_metadata}
 
+    def test_content_metadata_get_authorities(self, swh_storage, sample_data):
+        content1, content2, content3 = sample_data.contents[:3]
+        fetcher, fetcher2 = sample_data.fetchers[:2]
+        authority, authority2 = sample_data.authorities[:2]
+        (
+            content1_metadata1,
+            content1_metadata2,
+            content1_metadata3,
+        ) = sample_data.content_metadata[:3]
+
+        content2_metadata = RawExtrinsicMetadata.from_dict(
+            {
+                **remove_keys(content1_metadata2.to_dict(), ("id",)),  # recompute id
+                "target": str(content2.swhid()),
+            }
+        )
+
+        content1_metadata2 = RawExtrinsicMetadata.from_dict(
+            {
+                **remove_keys(content1_metadata2.to_dict(), ("id",)),  # recompute id
+                "authority": authority2.to_dict(),
+            }
+        )
+
+        swh_storage.metadata_authority_add([authority, authority2])
+        swh_storage.metadata_fetcher_add([fetcher, fetcher2])
+
+        swh_storage.raw_extrinsic_metadata_add(
+            [
+                content1_metadata1,
+                content1_metadata2,
+                content1_metadata3,
+                content2_metadata,
+            ]
+        )
+
+        assert swh_storage.raw_extrinsic_metadata_get_authorities(content1.swhid()) in (
+            [authority, authority2],
+            [authority2, authority],
+        )
+
+        assert swh_storage.raw_extrinsic_metadata_get_authorities(content2.swhid()) == [
+            authority
+        ]
+
+        assert (
+            swh_storage.raw_extrinsic_metadata_get_authorities(content3.swhid()) == []
+        )
+
     def test_origin_metadata_add(self, swh_storage, sample_data):
         origin = sample_data.origin
         fetcher = sample_data.metadata_fetcher