Lost actress Evangeline Lilly is refusing to join in with her cheeky co-star Matthew Fox's skinny-dipping sessions while filming in Hawaii, despite his determined attempts to persuade her to strip off.

The 26-year-old former model admits she is too self-conscious to go leaping naked into the sea, particularly in the presence of such a good-looking cast.

She says, "I haven't been lured into those yet, although Matthew's tried to persuade me.

"The first night he did it, we'd all gone to the beach and I ran into the water first with all my clothes on. I was swimming away and all of a sudden I heard hollering on the beach and Matthew is showing his bottom to the world.

"I've kept my clothes on and will continue to do so. I'm not a girl that is comfortable flaunting my body. I see all the flaws."