SYDNEY — Hugh Jackman said Wednesday that he is heartbroken his new film, "X-Men Origins: Wolverine," was leaked online a month before its official release.

The movie, which focuses on the beginnings of Jackman's clawed Marvel superhero Wolverine, is not scheduled for release in the U.S. until May 1, but a work print of the film began appearing online last week. 20th Century Fox said the FBI and Motion Picture Association of America were investigating and promised to prosecute those responsible.

The Australian actor, in Sydney to unveil 20 minutes of completed footage of the film to around 600 fans, said he was upset about the leak but still thinks fans will flock to see the movie in theatres.

"It's a serious crime and there's no doubt it's very disappointing -- I was heartbroken by it," Jackman said. "Obviously people are seeing an unfinished film. It's like a Ferrari without a paint job."

Jackman is on a world tour to promote the movie, making his first stop at Cockatoo Island in Sydney Harbor, where much of the film was shot. He arrived at the venue by helicopter before swooping to the ground on a zipline.