Sarah Larson models for Pucci

Clooney's girl, Sarah Larson, brightens up the Pucci catwalk

She was once an upmarket cocktail waitress and a contestant on US Fear Factor, but Sarah Larson can now add Pucci catwalk model to her growing resume.

The 28-year-old girlfriend of A-list actor George Clooney looked stunning as she sashayed down the catwalk in a sequin-covered, multi-coloured full-length dress with a sexy thigh-high split for Emilio Pucci at the Clark County Medical Society Alliance in Las Vegas.

It's not the first time the rising star has graced the catwalk – she caused a stir at LA Fashion Week when she sported swimwear on the runway for the Ashley Paige show, and we're pretty sure the model will become a regular face in the fashion world.

Meanwhile, George Clooney has reportedly launched a private investigation after receiving a threatening phone call warning him to split from Larson, who he has been dating since the summer of 2007.

In the message, a middle-aged man can be heard saying: 'Dude, your friends asked me to give you a message - dump the b***h before you're sorry!'

George doesn't believe the call is a prank by friends, and has enlisted the help of his former police officer chauffeur to trace the call to a pre-paid cell phone.