Simon Cowell has been rushed to hospital after having an accident at his London home, it has been reported.

The X Factor judge, 58, was allegedly carried out of his mansion in a neck brace after an ambulance was called to the premises at approximately 8am this morning, The Sun claims.

The music mogul is thought to have fallen down the stairs after fainting, and is currently undergoing tests in hospital. He is said to be in a stable condition.

A source close to Cowell told the newspaper: "It's been a scary morning. It was very early and Simon was going down his stairs to get some hot milk because he couldn't sleep.

"He fainted and is thought to have fallen down the stairs. An ambulance was called and he was stretchered out of the house in a neck brace surrounded by worried aides."

Cowell's girlfriend Lauren Silverman and son Eric were in New York at the time of the accident, but are now flying home to London to be with him.

Cowell is mentoring the groups on this year's X Factor and is scheduled to judge on the panel for the first live show of the series tomorrow night (27 October).

He has since returned home this afternoon, giving the paparazzi his famous thumbs up and looking tried and puffy-faced but on the mend.

It is not the first time Cowell has been struck down with exhaustion, as he collapsed in 2012 after his workaholic lifestyle took its toll on his wellbeing.

He told friends in that same year that running the X Factor and his other talent shows in America had left him with nervous exhaustion and living "like a weird vampire".