LONDON (AP) — A tense and sometimes hostile Piers Morgan refused to disclose details Tuesday about the most damning link between himself and Britain’s phone hacking scandal — his acknowledgment that he once listened to a phone message left by Paul McCartney for his then-wife Heather Mills.

The CNN celebrity interviewer, testifying through a video link from the U.S., clashed repeatedly with the UK panel investigating media ethics, insisting he never took part in the illegal phone hacking that has led to the closure of a Sunday tabloid he once edited and the arrests of friends and former colleagues.

The stakes were high for Morgan. More than a dozen journalists have been arrested, senior executives with Rupert Murdoch’s News Corp. media empire have lost their jobs, and top U.K. police officers have resigned over their failure to tackle the phone hacking scandal.

His testimony was given under oath, and Morgan could be subject to criminal proceedings if he is found to have violated any British laws.

Morgan’s defense Tuesday was part denial, part apology and a healthy helping of “I don’t recall.”

A key line of questioning centered on the comments Morgan made in a 2006 article he wrote for the Daily Mail tabloid. In it, Morgan said he was played a phone message left by the former Beatle on Mills’ answering machine.