In comments to U.S. television journalists delivered via videolink from Cincinnati, Ohio, McCartney said that he would be in touch with law enforcement as soon as he was finished with his summer tour.
"I will be talking to them about that," McCartney told the Television Critics Association in Los Angeles, just hours before a perfomance.
"I don't think it's great. I do think it is a horrendous violation of privacy, and I do think it's been going on a long time, and I do think more people than we know knew about it. But I think I should just listen and hear what the facts are before I comment," he said.
McCartney is the latest celebrity to be dragged into Britain's phone hacking scandal, which centers on allegations that journalists routinely eavesdropped on private phone messages, bribed police officers for tips and illegally obtained confidential information for stories.
Until recently the scandal was largely been limited to the British arm of Rupert Murdoch's media empire, but an allegation made Wednesday by McCartney's former wife Heather Mills implicates the Trinity Mirror PLC group of newspapers, and CNN celebrity interviewer Piers Morgan, who once edited the group's flagship Daily Mirror tabloid. It is one of several indications that the phone hacking scandal could yet spread to other British newspapers - even the Guardian, which helped unearth the scandal.
Mills' allegation, made Wednesday in an interview with the BBC, was that a senior Mirror journalist admitted to her that his paper had been spying on her messages. While the broadcaster said that the unidentified man was not Piers Morgan, the former model's allegation echoes a claim Morgan himself made back in 2006 - a few months after the couple began divorce proceedings.
In an article published by the Daily Mail, Morgan said that he had been played a tape of a message McCartney had left on Mills' cell phone in the wake of one of their fights.
"It was heartbreaking," Morgan wrote. "He sounded lonely, miserable and desperate, and even sang 'We Can Work It Out' into the answerphone."
Questions over how Piers Morgan came to hear such a message have led several British lawmakers to call on him to return to the U.K. and explain himself.
Morgan has so far not offered comment on his article, although he did describe Mills' allegation as unsubstantiated and noted that the judge in the couple's divorce case had cast aspersions on her credibility.
He has repeatedly denied having ever ordered anyone to spy on others' voicemails, while his former newspaper group has insisted that its journalists obey the law. Mills' office on Thursday declined to elaborate on what she told the BBC, but said that the 43-year-old "looks forward to receiving Piers Morgan's answer as to how he knew the content of her private voicemail messages."
Several British parliamentarians have also said that Morgan has questions to answer - among them Conservative legislator Therese Coffey.
"I think it would help everybody, including himself and this investigation, if he was able to say more about why he wrote what he did in 2006," Coffey told the BBC Wednesday.
Morgan's publicist, Meghan McPartland, said that as far as she knew the CNN star - who is spending his summer working as a judge on "America's Got Talent" - was not returning to England to answer questions.
Morgan himself made light of the calls on his Twitter feed, saying he found it "so heartwarming that everyone in U.K.'s missing me so much they want me to come home."
In a separate development, the publisher of Britain's Daily Mail newspaper announced late Thursday that it was reviewing its editorial procedures. No reason for the review was given, but Morgan is one of many media veterans who've claimed that phone hacking and other shady practices were common across Britain's newspaper industry.
And in what is surely one of the odder twists in the phone-hacking tale, it emerged that a senior journalist with the Guardian - whose aggressive investigative work helped air the scandal - had apparently acknowledged hacking into a phone.
"I've used some of those questionable methods myself over the years," David Leigh wrote in a piece published by the Guardian in 2006 and still posted to the paper's website.
The investigations editor described intercepting the voicemails of a corrupt arms company executive, admitting that there was "certainly a voyeuristic thrill in hearing another person's private messages."
But he insisted he was after a serious scoop, not celebrity gossip. In any case, Leigh wrote, "there is not a newspaper or TV channel in the country that has not, on occasion, got down in the gutter and used questionable methods."
The Guardian's press office was unstaffed early Friday morning. Leigh did not immediately return an email and a text message seeking comment.
Frazier Moore and Noaki Schwartz in Los Angeles and David Stringer and Jill Lawless in London contributed to this report.