A hapless robber has left police a key clue to help them find him - a series of photographs of his face.

According to police the man, who pried open the cash draw of an Illinois photo booth to steal $75, unwittingly left them three clear mugshots after the machine started snapping away as he committed his crime.

The pictures, taken on November 25, have now been developed and the Batavia Police Department are sharing the candid shots in a bid to catch the culprit.

In the pictures the man, dressed in a grey hoodie, black jumper and beanie, stares directly into the lens inside the Funway Amusements photo booth, seemingly unaware that the machine is recording his every move.

Unbeknownst to the robber the photo booth was actually designed to take photographs when it senses tampering to the cash drawer.