Tom Cruise has laughed off online speculation that he wore a prosthetic backside in his 2008 wartime thriller Valkyrie

The assumptions began in August, when a cheeky film fan tweeted a screengrab of Cruise in Valkyrie with the caption: "Hello, please, i present the theory that for one single shot in Valkyrie (2008), at 5:12, tom cruise wears a fake butt. observe."

US entertainment website Screen Rant was determined to get to the bottom of the story when it sat down with Cruise to talk about his new film American Made, and the star duly put the rumours in the rear view. 

"I have no idea," said Cruise. "There was no prosthetic in Valkyrie. No."

Tom Cruise with Domhnall Gleeson in American Made - "Let it be known - I do my own mooning"

The Valkyrie question had arisen during the rump of a discussion about Cruise's character Barry Seal's mooning in American Made, with the actor also reassuring Screen Rant that it was all his own 'work' in the new movie also.

"It's me," he said. "It's not CGI, it's me. I do my own mooning in films. So let it be known - I do my own mooning."