diff --git a/bin/add_ext_reference.py b/bin/add_ext_reference.py
index a6518cc..6e72c2d 100755
--- a/bin/add_ext_reference.py
+++ b/bin/add_ext_reference.py
@@ -25,7 +25,8 @@
 from ebi_eva_internal_pyutils.pg_utils import get_all_results_for_query, execute_query
 from retry import retry
 
-from eva_submission.eload_utils import check_project_exists_in_evapro, check_existing_project_in_ena
+from eva_submission.eload_utils import check_project_exists_in_evapro, \
+    check_existing_public_project_in_ena
 from eva_submission.submission_config import load_config
 
 logger = log_cfg.get_logger(__name__)
@@ -110,7 +111,7 @@ def main():
     if not check_project_exists_in_evapro(args.project_accession):
         logger.error(f'{args.project_accession} does not exist in EVAPRO')
         return 1
-    if not check_existing_project_in_ena(args.project_accession):
+    if not check_existing_public_project_in_ena(args.project_accession):
         logger.error(f'{args.project_accession} does not exist or is not public in ENA')
         return 1
     if _curie_exist(args.source_database + ":" + args.identifier):
diff --git a/eva_submission/eload_utils.py b/eva_submission/eload_utils.py
index d771887..d185a53 100644
--- a/eva_submission/eload_utils.py
+++ b/eva_submission/eload_utils.py
@@ -158,8 +158,12 @@ def check_project_format(project_accession):
     return re.match(r'^PRJ(EB|NA)', project_accession)
 
 
-@retry(tries=4, delay=2, backoff=1.2, jitter=(1, 3))
 def check_existing_project_in_ena(project_accession):
+    return check_existing_public_project_in_ena(project_accession) or \
+        check_existing_private_project_in_ena(project_accession)
+
+
+def check_existing_public_project_in_ena(project_accession):
     """
     Check if a project accession exists and is public in ENA
     :param project_accession:
@@ -172,6 +176,21 @@ def check_existing_project_in_ena(project_accession):
     return True
 
 
+def check_existing_private_project_in_ena(project_accession):
+    """
+    Check if a project accession exists and is private in ENA
+    :param project_accession:
+    :return:
+    """
+    try:
+        response = requests.get(f'https://www.ebi.ac.uk/ena/submit/drop-box/cli/reference/project/{project_accession}',
+                     auth=HTTPBasicAuth(cfg.query('ena', 'username'), cfg.query('ena', 'password')))
+        response.raise_for_status()
+    except requests.exceptions.HTTPError:
+        return False
+    return True
+
+
 # Create the databases if they do not exists. Then shard them.
 collections_shard_key_map = {
     "variants_2_0": (["chr", "start"], False),