British actor Timothy Spall studied painting for two years to prepare for his role as JMW Turner in Mike Leigh's critically acclaimed drama Mr Turner. The movie is steadily gaining Oscars momentum, particularly for Spall, whose grunting performance as the infamous artist is considered one of the finest of the year.

Mr TurnerTimothy Spall delivers one of the finest performances of the year in Mr Turner

Spall, probably best known to U.S audiences as Wormtail from the Harry Potter movies, even recreated Turner's famous Snow Storm - Steam-Boat off a Harbour's Mouth.

"They arranged for me to go and start learning to paint," said Spall. "I worked with this wonderful guy ... In the process, we started literally just still-life drawing, real-life drawing ... we eventually started using the materials Turner used. We eventually got to the point just before we started shooting where I did a full-scale copy in oil of (Turner's 'Snow Storm - Steam-Boat off a Harbour's Mouth')."

"I still don't know how I quite did it. I've got it on my wall at home and I say: 'How the hell did I do that?'"

More: read our full review of Mr Turner

For Leigh, Spall was the only actor he ever considered for the role.

"He just seemed right," said Leigh, "I knew he had some artistic leanings. More importantly, I knew he could do the sort of character I understood Turner to be. And also, Tim is a Londoner, which Turner was. Tim has read his Dickens, he's got a sense of period - you know he knows how to get into all that stuff. So it just seemed right, really."

Mr Turner goes up against the likes of The Hobbit: Battle of Five Armies, Annie and Night at the Museum 2 at the box-office this weekend and, although it will inevitably finish behind those heavyweights, it is the only movie on that list that is likely to be involved at the Oscars in February.

Watch the trailer for Mr Turner: