John Prescott uses parliamentary privilege in the House of Lords to allege that other Rupert Murdoch titles are being investigated

Other titles in Rupert Murdoch's media empire, including the Sunday Times, are being investigated for allegedly hacking into mobile phones belonging to well-known people, according to Lord Prescott.

The former deputy prime minister used parliamentary privilege to claim in the House of Lords: "The investigation into phone hacking has been extended now to the Sunday Times."

Scotland Yard announced a fresh inquiry into allegations of widespread phone hacking at the Murdoch-owned News of the World in January. The Met also told Prescott there was evidence his phone may have been targeted by Glenn Mulcaire, a private investigator who was employed by the paper.

Prescott used a Lords debate on the government's decision to approve News Corp's purchase of BSkyB to claim the practice of phone hacking was not restricted to the NoW. "It is a number of papers owned by the Murdoch press and a number of employees who have been involved in withholding evidence and [hacking into phones]," he said.

The claims were echoed in the Commons by Tom Watson, Labour MP for West Bromwich East, who said: "I now believe that evidence exists showing that journalists currently employed on the Times and the Sunday Times were involved in the phone hacking and that damaging revelations were printed in the Sun from information possibly collected by illegal hacking."

The claims prompted an immediate response from News International, which vigorously denied that any of its titles apart from the NoW were under investigation. "We do not believe Tom Watson has any evidence to support his allegation," a spokesman for the company said. "It is not a coincidence that he has made such cowardly and unsubstantiated claims under the cloak of parliamentary privilege. If he has any evidence we urge him to send it to us and we will take immediate action."

Watson said he had passed all information in his possession to the Metropolitan police. He launched a scathing attack on Rebekah Brooks, the former Sun and News of the World editor who is now chief executive of News International. "She may accuse me of being cowardly but she has resisted three attempts by a parliamentary committee to interview her over ... matters to do with phone hacking."

Brooks repeatedly refused to appear before the Commons culture, media and sport committee to answer questions about phone hacking on the grounds that she was not running the company when it took place.

Prescott called on the government to extend the three-week consultation period on the proposed BSkyBdeal until the Met's phone-hacking inquiry is completed.

Mulcaire was jailed for illegally intercepting messages left on mobile phones in January 2007 along with Clive Goodman, the News of the World's former royal editor.