A good samaritan who returned a stolen bike to its owner has been warned by police for buying stolen goods.

The man, who has been hailed as a “super-friendly guy who went above and beyond”, bought a silver bike for $60 off a man on Smith Street, Collingwood, last week before handing it into police and posting an ad on Gumtree in an effort to find the bike's rightful owner.

Mikey's first Gumtree ad, featuring a stolen bike he bought on the street, was viewed more than 50,000 times. Credit:Gumtree screengrab

According to Mikey*, the bike was in the possession of the same man he had bought another stolen bike off just a week earlier.

That bike was subsequently returned to its owner using the Gumtree website.