Actress Isla Fisher feared for her life when she filmed underwater scenes as an escapologist for upcoming movie Now You See Me after the chains she was wearing became tangled.

The Wedding Crashers star plays a glamorous daredevil in the new film, and one scene required her to be chained up and submerged in a tank of water.

Fisher had to appear to panic during the shoot - but she began to worry for real when her shackles got caught and she couldn't reach a safety button which would drain the tank.

She tells Britain's Mail on Sunday, "They had a guy who was off camera, but he was a long way away with a can of oxygen. By the time I realised I couldn't get up and beckoned for him, I realised that I had run out of air.

"Luckily, I managed to get free and stay level-headed and got out before it went even more horribly wrong. The director (Louis Leterrier) said to me, 'Wow. I've worked with so many actors on big action movies, and you're the only one who's done all their own stunts.' I said I didn't know I had a choice. I thought you just had to get on with it."