Usher to play boxer Sugar Ray Leonard

Usher has confirmed that he's set to play Sugar Ray Leonard in an upcoming boxing film called Hands Of Stone.

Leonard, a world champion in five different weight divisions, finally retired from boxing in 1997 after a number of comebacks.

The film is about legendary Panamanian boxer Roberto Durán.

The R&B star said he was in training for the role in the film which he says will also star Robert De Niro and Gael García Bernal.

"I'm in preparation for a very incredible role," Usher said.

"If you guys see me running around London that's what it is.

"If you see me in the corners boxing. I'm doing that while working on this album."

The singer confirmed he'll start filming for the movie later in 2012.

He also said De Niro is cast as legendary boxing trainer Ray Arcell - who coached 18 world champions including Durán.

Usher, who has scored huge hits with tracks like Yeah!, admitted that he's yet to meet Leonard in person.

Usher has appeared on screen before, most recently in 2010 film Killers.

Usher's 2004 Confessions is currently the biggest selling album of the 21st century so far.