Urban's Dredd-ed film preparation

Karl Urban has revealed that he had to undergo a gruelling fitness regime for his role in Dredd.

The New Zealand star, who portrays law enforcement officer Judge Dredd in Pete Travis' sci-fi thriller, had to cut down on fast food and alcohol, and start working out.

"The first thing I had to do as my preparation for the film was to stop drinking beer and eating hamburgers. I then had to start lifting lots of heavy things multiple times per day, and a lot of gym work. I found that a daunting proposition," he said at London Film & Comic-Con.

"I was working out twice a day, eating six times a day and every time I would come back, there were my pile of Dredd comics with this ripped figure just goading me."

Karl, who also appeared at San Diego's Comic-Con International, keeps the iconic helmet on throughout the film, unlike 1995's Judge Dredd, starring Sylvester Stallone in the title role.

"This one was an extraordinary challenge. First off the bat, knowing that I wasn't going to have the benefit and use of my eyes, which is a valuable tool for an actor," he explained.

"How do I convey as much as I can without my eyes? The voice becomes very important, body language, humour and it's really amazing when that comes across."

But Karl, who has also appeared in The Lord Of The Rings, Star Trek and RED, is proud to step into the iconic role: "I consider myself a long-term fan of Dredd. I started reading it when I was about 15."

Dredd, which also stars Olivia Thirlby, Lena Headey and Domnhall Gleeson, opens in UK cinemas on September 7.