Matthew Fox is allowing his favourite tattoo artist to use his body as a canvas - the actor has no idea what the design on his arm will become.

The former Lost star had his first skin art when he was 20 and now he has lost count of his many tattoos all over his body - and his latest is a mystery, even to him.

He tells U.S. Tv talk show host Ellen DeGeneres, "This is new stuff that I'm working on... It's kind of mysterious right now. It'll need a couple more sessions and then it will come together.

"The artist who's doing it knows what it's gonna be."