diff --git a/middleware/app_be/views/rest_api.py b/middleware/app_be/views/rest_api.py
index 0304d99..791e08d 100644
--- a/middleware/app_be/views/rest_api.py
+++ b/middleware/app_be/views/rest_api.py
@@ -51,7 +51,26 @@ class ImageEndpoint:
     @staticmethod
     @api_view(['GET'])
     def image_api_get_status(request, identifier):
-        # TODO MARTIN
+        # get metadata from MongoDB
+        metadata = MongoDBService.getSingle(identifier)
+        if not metadata:
+            return JsonResponse({'valid': False, 'available': False})
+
+        # get stored SHA512 hash
+        stored_hash = metadata.get('sha512', '')
+        no_image = True
+
+        for service in ImageEndpoint.storageServiceList:
+            service_image_bytes = service.read_file(metadata['filename'])
+            if service_image_bytes is not None:
+                no_image = False
+                actual_service_hash = create_sha512(service_image_bytes)
+                if stored_hash != actual_service_hash:
+                    return JsonResponse({'valid': False, 'available': True})
+
+        if no_image:
+            JsonResponse({'valid': False, 'available': False})
+
         return JsonResponse({'valid': True, 'available': True})
 
     @staticmethod