Police in the UK are reportedly probing a threat against Cheryl Cole - which was left on 'X Factor' host Dermot O'Leary's mobile telephone.
The Sun reports that a shocked O'Leary raised the alarm when he heard the vile voicemail aimed at 'X Factor' judge Cheryl, 26.
A source said: "The message was of a sexual, threatening and sickening nature. Dermot was horrified when he heard it.
"He thought at first it was a sick wind-up, but soon realised there was something sinister going on."
The source added: "Somehow this caller has tried to get hold of her number and somehow accidentally got Dermot's.
"If they were prepared to go to that effort, who knows what they would be prepared to do?"
Cheryl is understood to have been alerted to the threat but it has not been played to her.
A spokesman said her management are helping police with inquiries.
"We are investigating claims of an offensive message being left on a mobile telephone," a City of London Police spokesman said.
"It follows a complaint from a member of the public."
Security for 'The X Factor's judges was upped in 2008 after a tracking device was put into show supremo Simon Cowell's car.
Cowell, 50, is said to have "freaked out" when he found it in his Bentley after spotting a mystery biker lurking outside his private meetings.
