Kate Hudson didn't want her fiance to watch her giving birth, but he was adamant about "getting his hands dirty".

The Hollywood actress and her musician beau Matt Bellamy welcomed their son Bingham into the world in July last year.

Although the Muse rocker was determined to be as involved as possible, Kate wasn't so sure.

"Oh yeah, I was there at the birth. I was watching the whole thing," he explained to Q magazine. "I was holding her leg up when she pushed him out. She didn't want me to watch but I was there, getting my hands dirty, so to speak."

British rockers Muse provided the official anthem for the London 2012 Olympic Games with their song Survival.

The soaring anthem is full of wailing guitars and heavy drums and was initially very different to how it turned out.

"That song you won't believe I'm about to use the word subtle'," he laughed. "Of course, we're aware how crazy, even silly, that is. But when they first approached us about doing something for the Olympics, it was actually for quite a subtle usage. Maybe a bit more mysterious than it turned out."