Australian police have released CCTV footage of a cross dressing robber holding up a fast food restaurant in Melbourne.

The video shows a man approaching staff at the counter of a restaurant in Laverton North in Melbourne at 7.45am on Sunday (8 February).

It is alleged the man demanded cash while holding what he said was a detonator in a paper cup.

"When there's talk of an explosive device it does make people even more uneasy. In this case we have no evidence to show that there was an explosive device at the scene but obviously we're going to be investigating that thoroughly and once we find this male charges will be pending in relation to that," said Victoria police Detective Senior Constable Lloyd Felber.

The man fled the scene, dropping some of the money in the process.

The robber is described as tall although it is not clear how high his heels are. He is said to have a chiselled jaw and heavy stubble.