Heather Mills has claimed a Mirror Group journalist admitted hacking into voicemails left for her by Sir Paul McCartney.

The Hove resident told BBC’s Newsnight that a journalist quoted parts of a voice message from her ex-husband when asking for a comment on a story in 2001.

When challenged about how they knew what was said, Ms Mills said they admitted the message had been hacked.

The identity of the journalist has not been revealed, although the BBC has said it is not former Daily Mirror editor Piers Morgan.

Mr Morgan issued a statement describing Ms Mills’ claims as “unsubstantiated” and said it had been stated during her divorce proceedings that she had illegally intercepted Sir Paul’s telephone calls and leaked them to the media.

He said: "No doubt everyone will take this and other instances of somewhat extravagant claims by Ms Mills into account in assessing what credibility and platform her assertions are given.

"And to reiterate, I have never hacked a phone, told anyone to hack a phone, nor to my knowledge published any story obtained from the hacking of a phone."

In a 2006 article for the Daily Mail he admitted hearing a recorded message Sir Paul had left Ms Mills, saying it was “heartbreaking”.

A Trinity Mirror spokesman said: "Our position is clear. All our journalists work within the criminal law and the PCC code of conduct."