Melbourne Embona Task Force detectives are appealing for information after an attempted armed robbery in Richmond.

Investigators have been told a man armed with a knife approached a young boy riding a scooter on Egan St, near the intersection of Station St, on Monday, August 8, about 3.35pm.

The man threatened the boy and made demands for his scooter.

The boy was able to ride away from the man and was not physically injured during the incident.

Investigators have released computer generated images of a man they believe may be able to assist with their enquiries and the weapon used in the incident.

He is perceived to be Caucasian in appearance, about 30-years-old with a medium build, short dark hair and a freckled nose.

He was wearing a brown leather jacket, red t-shirt, black tracksuit pants and black shoes.