Kylie Minogue and Olivier Martinez split

They said the decision to separate was mutual and added that they remained "very close friends".

A joint statement released on behalf of the pair read: "Olivier Martinez and Kylie Minogue have officially confirmed that they are no longer a couple.

"They have made it clear that the decision to go their separate ways was mutual and amicable. "The media's false accusations of disloyalty have saddened them both. The two remain very close friends."

The separation comes at the end of a tumultuous time for Minogue after she was diagnosed with breast cancer.

The singer was forced to abandon her Showgirl world tour in May 2005, and did not resume it until last November.

The 38-year-old singer spoke of how her "incredible" boyfriend of four years had helped her through the darkest days of her cancer battle.

She said going through treatment felt "like being in an atomic explosion", but the support of Martinez, 41, was invaluable.

Last November Minogue told Elle magazine: "On particular dark days, I'd be lying on the bathroom floor wailing and he'd say, 'OK, honey, you can cry for just five minutes, then I'm taking you on the bike for a ride around Paris'. "So I'd howl a bit more and then I'd find myself thinking, 'Hmm. Actually, a ride on the bike sounds pretty good.'

"Olli was there all the time, helping with the practical stuff and being protective.

"I don't like to say too much in public about Olivier as he's a very private person, but I will say that he was incredible.

"He didn't hesitate in cancelling work and putting projects on hold so he could be with me. He's the most honourable man I have ever met." At the time she denied reports the couple were planning to marry.

"I understand the excitement at the prospect of a wedding, but we're simply happy together and getting on with life," she said.

Last April pictures taken by Martinez showing Minogue was on the road to recovery were posted on her website.

The star was shown looking happy and healthy with a full head of hair, only months after finishing chemotherapy treatment for breast cancer.

They were taken as the pair took a break together in Portofino on the Italian Riviera.

The pictures showed a marked improvement from earlier in 2006, when the singer was photographed in Paris with her face and head hidden under a hat and sunglasses.