diff --git a/swh/web/ui/service.py b/swh/web/ui/service.py
--- a/swh/web/ui/service.py
+++ b/swh/web/ui/service.py
@@ -74,8 +74,8 @@
 
     Args: query string of the form <hash_algo:hash>
 
-    Returns: Dict with key found to True or False, according to
-        whether the checksum is present or not
+    Returns: Dict with key found containing the hash info if the
+    hash is present, None if not.
 
     """
     algo, hash = query.parse_hash(q)
@@ -84,6 +84,20 @@
             'algo': algo}
 
 
+def search_hash(q):
+    """Checks if the storage contains a given content checksum
+
+    Args: query string of the form <hash_algo:hash>
+
+    Returns: Dict with key found to True or False, according to
+        whether the checksum is present or not
+
+    """
+    algo, hash = query.parse_hash(q)
+    found = backend.content_find(algo, hash)
+    return {'found': found is not None}
+
+
 def lookup_hash_origin(q):
     """Return information about the checksum contained in the query q.
 
diff --git a/swh/web/ui/tests/test_service.py b/swh/web/ui/tests/test_service.py
--- a/swh/web/ui/tests/test_service.py
+++ b/swh/web/ui/tests/test_service.py
@@ -107,6 +107,45 @@
 
     @patch('swh.web.ui.service.backend')
     @istest
+    def search_hash_does_not_exist(self, mock_backend):
+        # given
+        mock_backend.content_find = MagicMock(return_value=None)
+
+        # when
+        actual_lookup = service.search_hash(
+            'sha1_git:123caf10e9535160d90e874b45aa426de762f19f')
+
+        # then
+        self.assertEquals({'found': False}, actual_lookup)
+
+        # check the function has been called with parameters
+        mock_backend.content_find.assert_called_with(
+            'sha1_git',
+            hex_to_hash('123caf10e9535160d90e874b45aa426de762f19f'))
+
+    @patch('swh.web.ui.service.backend')
+    @istest
+    def search_hash_exist(self, mock_backend):
+        # given
+        stub_content = {
+                'sha1': hex_to_hash('456caf10e9535160d90e874b45aa426de762f19f')
+            }
+        mock_backend.content_find = MagicMock(return_value=stub_content)
+
+        # when
+        actual_lookup = service.search_hash(
+            'sha1:456caf10e9535160d90e874b45aa426de762f19f')
+
+        # then
+        self.assertEquals({'found': True}, actual_lookup)
+
+        mock_backend.content_find.assert_called_with(
+            'sha1',
+            hex_to_hash('456caf10e9535160d90e874b45aa426de762f19f'),
+        )
+
+    @patch('swh.web.ui.service.backend')
+    @istest
     def lookup_hash_origin(self, mock_backend):
         # given
         mock_backend.content_find_occurrence = MagicMock(return_value={