The former editor of The Mirror, Piers Morgan, was under intense pressure last night after Sir Paul McCartney's ex-wife came forward to claim a journalist had bragged to her about hacking sensitive messages left on her phone.
Heather Mills said she received a call from an executive at Mirror Group Newspapers in 2001 "quoting verbatim" voicemails left by the singer after the couple had had a row.
Her comments undermine Mr Morgan's claim that he knew nothing about phone hacking – as the voicemails appear to be the same as those which he later admitting hearing.
In a 2006 newspaper article, Mr Morgan referred to hearing a recorded message which Sir Paul had left for Ms Mills while she was away in India.
He wrote: "At one stage I was played a tape of a message Paul had left for Heather on her mobile phone.
"It was heartbreaking. The couple had clearly had a tiff, Heather had fled to India, and Paul was pleading with her to come back. He sounded lonely, miserable and desperate, and even sang 'We Can Work It Out' into the answer phone."
Last night Ms Mills said: "There was absolutely no honest way that Piers Morgan could have obtained that tape that he has so proudly bragged about unless they had gone into my voice messages." However she said the journalist who contacted her was not Mr Morgan.
Ms Mills told BBC Newsnight that she had already been suspicious that her voicemail had been intercepted before she was contacted. "He [the journalist] said, 'I hear you've had a big argument with your boyfriend', and I said, 'why would you know this?' And he started quoting verbatim the messages from my machine," she said.
"I [had already] wondered why [my messages] had already been listened to when it said 'heard messages'. And he started laughing and I said, 'why are you laughing?' I said, 'you've obviously hacked my phone and if you do anything with this story... I'll go to the police'."
She said he responded: "OK, OK, yeah we did hear it on your voice messages, I won't run it."
Mr Morgan hit back last night, casting doubt on the reliability of Ms Mills' comments. He said: "Heather Mills has made unsubstantiated claims about a conversation she may or may not have had with a senior executive from a Trinity Mirror newspaper in 2001.
"The BBC has confirmed to me that this executive was not employed by the Daily Mirror. I have no knowledge of any conversation any executive from other newspapers at Trinity Mirror may or may not have had with Heather Mills." Mr Morgan also raised what he said were previous instances of "extravagant claims" made by Ms Mills, and repeated a denial that he had any involvement in phone hacking.
Parent group Trinity Mirror said: "Our position is clear. All our journalists work within the criminal law and the PCC code of conduct."
Newsnight also claimed that the footballer Rio Ferdinand and TV presenter Ulrika Jonsson believe they were hacked by the Mirror group.