The bash was held at the plush Nikki Beach Club in St Tropez, France, to celebrate the launch of Silvstedt's new underwear range.

But chaos ensued after a champagne-drinking marathon, during which guests - including unnamed pop stars, models and members of the Swedish royal family - allegedly started pushing each other into the water.

And medics had to be called out to the party when a woman was spotted lying motionless at the bottom of the pool. The unnamed woman spent six hours in hospital before being released.

Guest NICOLA CHESSA tells British newspaper The Sun, "They had a sort of champagne race. They were crazy with all that champagne.

"They ordered hundreds of bottles and started to party and pushed one another into the pool.

"After a while someone shouted that there was a woman lying immobile in the pool. It was all extremely scary."