Kate Winslet has described how she undertook a dramatic rescue effort after a fire broke out in Richard Branson's private home on Necker Island in August.

The actress said her first action when she realised a blaze had broken out was to reach for her bra.

"We woke up at 4:30 in the morning to yelling that there was a fire," the 36-year-old Contagion star told The Graham Norton Show, in an episode to air on 29 October. "I jumped up and ran immediately towards the fire but then realized we might die … then thought 'Now what do I do?' so I ran into the bedroom and put on a bra!"

"In disastrous moments like that, you do the strangest things. I started to put on a bra and thought 'No, that's going to take me too long,' so off came the bra, on came the T-shirt, then I grabbed the children and I picked up granny (Richard Branson's mother Eve)," she went on.

Branson publically credited Winslet with looking after his mother in the fire, which destroyed the main house on Necker Island (above, second right) but left no-one hurt.

"Many thanks to Kate Winslet for helping to carry my 90 year (old) mum out of the main house to safety," Branson said at the time, joking that Winslet "was wondering when a director was going to shout 'CUT!'"

But appearing on the Norton show, the Oscar winner denied her role had been heroic, saying: "No I didn't save her life. I carried her down the stairs is the truth of it. I have to say Eve Branson is an extraordinary stoic, powerful lady and she could have totally made it out on her own, I just helped that tiny little bit."

Winslet was staying on the island with her two children - Mia, 10, and Joe, seven - and her boyfriend Louis Dowler at the time of the incident.

Kate Winslet recalls fire rescue