Whittlesea Crime Investigation Unit detectives are appealing for assistance from the public following an armed robbery in Whittlesea last month.

Investigators have been told an unknown man walked into a service station on Plenty Road on Thursday 28 July about 12.30am.

The man approached the service station attendant armed with large silver machete and made demands for cash.

The attendant handed over a quantity of cash and then pressed a duress alarm.

Police have been told the man then exited the store heading north on Plenty Road.

Investigators have released CCTV footage and images of a man they would like to speak to in relation to the incident.