MELBOURNE (REUTERS).- Thieves have stolen a valuable painting of a rat carrying a suitcase, by the anonymous British graffiti artist Banksy, from a meter box outside a house in the Australian city of Melbourne, police said on Thursday.

Police said the artwork was stolen between April 24 and May 15 from the door of a meter box outside the Melbourne home of underwear designer Mitch Dowd, but the theft was only discovered recently because Dowd had been out of town.

The theft came shortly after the value of the artist's work hit the headlines when street cleaners in Melbourne painted over a stencil of a rat by Banksy elsewhere in the city.

Dowd said it was disappointing that thieves had targeted the artwork by the secretive Banksy, one of the world's top street artists whose real identity remains unknown.

"The house faces right onto the pavement so everyone would walk by and see it all the time and now all that's there is a black box," Dowd said in a statement.

"It's a well known rat carrying a suitcase that's about eight inches high. It's black on a red background and it's been there for over a year. It's sad that as soon as the articles on Banksy came out that people would think it was valuable."

Banksy is famous for illegal outdoor graffiti, including painting the West Bank barrier and leaving a life-size figure of a Guantanamo Bay detainee at California theme park Disneyland.

From a small-time graffiti artist to a global star, Banksy's work has become so valuable that several of his street works have been salvaged and sold, including a painting on a London wall that fetched 208,100 pounds ($340,000) in 2008.

(Writing by Belinda Goldsmith, Editing by Michael Perry)