LONDON — Rupert Murdoch’s media empire suffered a potentially heavy blow in the British phone-hacking scandal Tuesday when Parliament released documents suggesting that reporters and top editors at the News of the World practiced and sanctioned the illegal interception of voicemails.

An internal letter written in 2007 by Clive Goodman, a former reporter at the tabloid and the only one convicted so far in the scandal, alleged that phone hacking had the “full knowledge and support” of others at the paper and was “widely discussed” at daily editorial meetings.

The statements directly contradict the paper’s insistence that hacking was confined to a single “rogue reporter,” Goodman, who was sent to jail for tapping into the voicemails of members of Britain’s royal household.

News International, the British arm of Murdoch’s News Corp. and the owner of the now-defunct News of the World, said in a statement that it recognized the seriousness of the letter and that it was “working in constructive and open ways” with both Parliament and the police.

Lawmakers have now summoned four senior figures at News International and the News of the World to reappear next month before a parliamentary committee looking into the scandal.

Two members of the committee said they were likely to recall Murdoch’s son, James Murdoch, chairman of News International, to answer allegations that he gave misleading evidence during a hearing of the panel last month.

Murdoch had told lawmakers that, in authorizing a large out-of-court settlement with a former soccer star whose phone had been tapped into, he was unaware of an e-mail in the case suggesting more than one journalist was involved in hacking.

In a March 2007 letter addressed to the human resources director of News International, Goodman demanded that he be reinstated to his job at the weekly tabloid despite his conviction and imprisonment on phone-hacking charges.

Goodman had pleaded guilty to illegally accessing messages left for aides to Britain’s royal family. But he wrote that the subsequent decision to fire him was “perverse” and “inconsistent” because of the internal common knowledge of the phone hacking.

In another potentially explosive passage, Goodman said the paper had promised that he could return to his job if, in essence, he agreed to be the fall guy.

“I expect the paper to honor its promise to me,” Goodman wrote, since he “did not implicate the paper or any of its staff” in his guilty plea.

His letter was part of a raft of correspondence released by Parliament’s committee on culture, media and sport, which has been investigating the hacking scandal.

Committee member Tom Watson, one of the most dogged critics of the News of the World, said the letter was “devastating” to the contention by company executives that phone hacking was the work of one rogue reporter.

James Murdoch is likely to be summoned before the committee again to explain discrepancies between the evidence he gave last month and new allegations that have since come to light, Watson and committee Chairman John Whittingdale said.