Kiwi filmmaker Taika Waititi demanded Chris Hemsworth go shirtless in Thor: Ragnarok, a move sure to delight the Aussie hunk's fans.

It's the sixth film the blonde 34-year-old has played the god of thunder in and the New Zealand director insists his ripped torso will help ticket sales.

Hemsworth stripping half nude has become a staple of the Thor movies, but the 34-year-old was relieved he originally didn't have to in the new film - until Waititi forced him to.

"In the very first Thor, I'd be training for months and months and months and Kenneth Branagh said 'What do you think about a shirt off scene?' I said 'Mate, I've been killing myself in the gym for eight months - I'm ready! Let's go!" Hemsworth tells Yahoo Entertainment.

"This time round, there wasn't one in the script. I thought, thank God. Then Taika came up to me and said, 'I feel like we got to put it in there, come on. Let's be gratuituous and see some skin."

The Hunt for the Wilderpeople filmmaker confirms Hemsworth's story - adding that there's plenty more footage of his bulging naked muscles coming when the film is released on DVD.

"I was like, 'Chris, you have to take your shirt off'. And he was like, 'Oh, they always make me take my shirt off in these movies!' But I told him we wanted bums on seats," says Waititi.

"I would say on the DVD you can expect a whole extra DVD just of that - four hours of him, slow-motion, black and white, black and chrome, full colour, IMAX version, iPhone version."

Thor: Ragnarok opens in New Zealand cinemas today.

Newshub.