Lindsay Lohan's 'knife pal' Vanessa Minnillo regrets her behaviour with the young star, according to reports.

Pictures of the pair cavorting with knives and pulling at each others' tops in June last year were leaked onto the internet last week.

But Minnillo, who is now dating pop star Nick Lachey, is allegedly ashamed by her behaviour, which took place after a night out at New York club Bungalow 8.

A source tells American publication Us Weekly, "(Minnillo) got caught up in the moment and thought it would be fun."

"It was stupid and she regrets it. They were only fooling around."