She said the recording he has boasted of hearing had been illegally hacked.

Morgan has consistently denied authorising phone-hacking when he was a tabloid newspaper editor in Britain. He has not yet explained how he came to hear the message on Heather Mills's cellphone.

The accusation has dragged Morgan into the phone-hacking scandal that has damaged Rupert Murdoch's media empire and has had widespread ramifications for the British press.

Testifying at an inquiry into British media ethics, Mills said she had left a house she shared with McCartney in early 2001, after they had a row. She had turned her phone off.

The next morning, she said, she had received about 25 messages on her phone, all of which appeared to have been listened to, including one in which McCartney "sang a little ditty of one of his songs". She said she deleted the messages.

Later that day, a reporter called her to say he had heard the couple had argued and that McCartney had left a message in which he sang to her. This, she told the inquiry, could only have meant her phone had been hacked.

The inquiry was told the unnamed reporter was a former employee of the Trinity Mirror Group though not from the Daily Mirror, one of the group's papers, which Morgan edited from 1995 to 2004.

Asked if she had ever made a recording of McCartney's call or had played it to Morgan herself, Mills said: "Never".

Mills, who married McCartney in 2002 and divorced six years later, said Morgan - "a man that has written nothing but awful things about me for years" - would have relished telling the inquiry if she had played a personal voicemail message to him.

Testifying in December Morgan, who bragged about seeing the message in a newspaper column in 2006, refused to say who played him the recording of the call, saying he was protecting a source.

Morgan edited the now defunct News of the World tabloid that was at the centre of the hacking scandal, from 1994 to 1995, before the practice became rife. He boasted that he knew about phone hacking well before the scandal broke, but subsequently said he was referring to rumours.

Morgan wrote in his diaries about a "little trick" for eavesdropping on voicemails that he heard of as early as 2001.

One former Mirror employer told the inquiry that hacking was widespread on the paper when Morgan was editor, and Trinity's chief executive has said some reporters might secretly have engaged in the practice.

British police felt the heat too, accused of failing to investigate allegations that Murdoch's News of the World tabloid had hacked into the phones of thousands of people.