Brimbank Crime Investigation Unit detectives are investigating an armed robbery at a service station in Watervale last Monday.

Investigators have been told a man dressed in female clothing entered the service station on Taylors Road in Taylors Hill just before 7.30pm on 30 March.

He walked to a drink fridge and then to the counter where he confronted the female staff member.

He produced what appeared to be a home-made machine gun from a black bag and demanded money.

The staff member handed over a quantity of cash which he has placed in the bag, along with the fake firearm, and exited the store.

There were customers in the store at the time however no one was injured during the incident.

Detectives have released an image of a man that may assist with their enquiries. At the time of the incident he was wearing what appeared to be womens clothing.