'Just pals': Justin Timberlake and Mila Kunis star in new film Friends With Benefits but a source has denied claims their friendship is behind his split with Jessica BielJustin Timberlake and Jessica Biel announced last week that their four-year relationship is over - and Black Swan actress Mila Kunis was rumoured to be behind the split.
But a source close to the Sexy Back singer is insisting that it is simply not true.
'Mila had nothing to do with their break-up', the source said. 'In fact, no one came between them.'
'They decided their relationship ran its course and it was time to move on', the insider told People magazine.
Stories in the US have claimed that the Black Swan actress and the pop star have been 'flirting' with each other since September when they met on the set of their upcoming film Friends With Benefits.
The source said: 'They're not in a relationship. They star in a movie called Friends With Benefits but they're just friends. That's it. They are not together'.
Gym Junkie: Mila was spotted leaving a West Hollywood gym todayBut another insider said that although the pair remain platonic, they have great chemistry and Justin is 'very interested' in Kunis, 27.
Speaking to E! Online, a source said: 'Justin is very interested in Mila.
'They've been flirting. But so far nothing has happened.'
Another source told celebrity blogger Perez Hilton that the pair had been very 'flirty' with each other on set, leading him to suggest that something may now happen between the two now that Timberlake is single again.
Separate ways: Justin Timberlake and Jessica Biel, pictured at the Vanity Fair party in February, announced the end of their four-year relationship last weekThe two also joined forces to present an award at last year's Oscars and to some observers, their 'giggling chemistry' was all too apparent.
And they gushed about each other on the red carpet, with Timberlake telling E! Online's Marc Malkin that shooting sex scenes with Kunis wasn't a hard thing to do.
He said: 'That's an easy thing to do. I think I could speak for all the men in the world when I say that's the easy part.'
Close friends: Onlookers said Timberlake and Kunis's chemistry was obvious when they presented an award at the Oscars last monthAnd her praise was just as gushing when she spoke about him to MTV at the Cosmopolitan's Fun Fearless Males party last Monday.
She said: 'He's just as lovely, just as professional, just as sweet and amazing, and there's nothing that he can't do.'
Timberlake and Biel announced their split yesterday after four years together.
Meanwhile, Kunis split from Home Alone star Macaulay Culkin in January after an eight year relationship.
Meanwhile Jessica Biel put on a brave face as she made her first public appearance since news of her split.
The A-Team actress went to her brother's birthday party last night looking like she did not have a care in the world.
Biel walked in Cafe Entourage with a male friend and strode happily and confidently past the waiting photographers.
Brave face: Jessica Biel appeared publicly for the first time since the split from Timberlake - she attended her brother's birthday party in Hollywood, CaliforniaThe split between Justin, 30, and Jessica came after a 'very awkward' surprise birthday party thrown by Jessica for her lover.
A source told MailOnline: 'Jessica was overcome with emotion when she stood up to toast her boyfriend on reaching the milestone.'
During the birthday speech, the actress gushed about how utterly head over heels in love she was with the singer-turned-actor and went on at length about how much he meant to her.
But after Jessica had finished her speech, Justin appeared dismiss her emotional speech by standing up and yelling: ‘Yeah b*tches!’
source: dailymail