Fawkner Embona Taskforce detectives are investigating two armed robberies in Ascot Vale over the past fortnight.

Investigators have been told the thief first struck at a 24-hour convenience store on Mt Alexander Road on 21 March.

The man first entered the store around 4am and threatened a staff member with a firearm, demanding cash and cigarettes.

The attendant handed the items over and the robber placed them in a red enviro bag before leaving the scene.

Just after 3.15am on 1 April a man has entered the same store and again threatened the attendant with a firearm.

A quantity of cigarettes and cash were handed over and the man left the store.

Detectives are investigating the incident and have released CCTV and an image of a man who they believe may be able to assist with their enquiries.