Have you seen this man?

South West detectives are hoping CCTV footage from an armed hold-up at Shell Gateway in Glen Iris on Tuesday will help with their investigation.

A man threatened an attendant with a big kitchen knife, before demanding cash then fleeing on foot.

The man is described as being fair-skinned, approximately 183cm tall and wearing dark clothing.

Anyone with information can contact Crime Stoppers on 1800 333 000.