Karl Urban says a 'Dredd' sequel could be happening.

The action film, which was released in September last year, performed disappointingly at the box office resulting in production company Lionsgate Entertainment not committing to a sequel, but Karl thinks there is a significant enough fanbase to produce another film.

Talking at the San Diego Comic-Con last weekend, he said: ''The home video sales just went through the roof. I think it sold 650,000 units in the first week.

''I think the more people that campaign for it, the more people that email, Twitter and write into Lionsgate and say, 'We want to see more of this', then the more likelihood that we'll get to see that.

''We certainly are doing everything we can to ensure that happens.''

The 41-year-old actor played the title role of Judge Dredd, an all-powerful judge, juror and executioner who must take down a gang that deals a reality-altering drug in the futuristic thriller.

Karl has always been keen to turn the sci-fi flick - based on the 2000 AD comic strip Judge Dredd - into a cult franchise following the success of superhero smash hits like 'The Amazing Spider-Man', 'The Dark Knight Rises' and 'The Avengers Assemble'.

He previously said: ''We're releasing the film and we're handing it over to an audience. If they embrace it, we'd love to come back and continue the story. The potential is limitless.''