Police are investigating the armed robbery of a supermarket at Helensvale this afternoon.

Around 12.25pm a man entered the Monterey Keys Drive store and approached the front counter.

He attempted to remove a cash register but was unsuccessful and then threatened an employee with a stolen knife.

The staff member opened the register before the man stole cash from the till.

After being confronted by other employees, the man fled the scene with a sum of cash.

No one was physically injured during the incident.

The man is described as being Caucasian in appearance, aged in his late 20s, with a thin build and brown hair. He was wearing a grey t-shirt, white shorts, black shoes and a black cap.

He was last seen leaving the scene in a blue 1994 Holden Commodore sedan.