Police have appealed for help to identify a person who robbed a man at gunpoint outside a bank in Broadmeadows then fled in a getaway car.

Investigators believe the suspect approached a man, who was carrying a backpack, and demanded him to hand over the bag outside a shopping centre plaza on Pascoe Vale Road on May 2.

The suspect then allegedly pulled out a handgun and the victim handed over the bag which contained a substantial amount of cash.

The offender fled the scene in a late model silver Mercedes, which was waiting nearby, and sped off towards Pearcedale Parade.

The suspect is described as 175cm tall, with a thin build. He was wearing a white hooded jumper, face mask and grey pants.