MELBOURNE City Council sent the cleaners into Hosier Lane on Thursday to tidy up the rat-infested garbage, but they caught the wrong rat.

A request by deputy lord mayor Susan Riley to clean up the laneway, world famous for its colourful street art, inadvertently resulted in the painting over of a stencil of a rat by the celebrated British graffiti artist Banksy.

''I went down there on Thursday and saw the cleaners and said: 'You realise you have just painted over a Banksy?','' Hosier Lane resident Kerry Butcher told The Age yesterday. ''And they said: 'We are just doing what we're told'.''

Banksy, who created several stencils in Melbourne on a visit in 2003, is regarded as the world's foremost street artist. In 2008, a London wall bearing one of his stencils allegedly sold on eBay for $472,528. His works on paper sell at auction for hundreds of thousands of dollars.

Last week lord mayor Robert Doyle was pictured in The Age under a stencil of himself in Hosier Lane as he praised its street art as a ''legitimate expression of artistic intent''.