London (CNN) -- Parliament released new documents Tuesday that cast doubt on the veracity of testimony given to lawmakers last month by James Murdoch, the son and heir apparent to Rupert Murdoch's media empire, about News International's role in the phone hacking scandal.
James Murdoch has denied having known about an e-mail that included transcripts of 35 hacked conversations. The e-mail is believed to have been intended for Neville Thurlbeck, who was then chief reporter for the now-defunct tabloid, News of the World.
The existence of the "for Neville" e-mail was disclosed during the settlement of a case brought against News International by Gordon Taylor, the former U.K. soccer chief.
James Murdoch signed a check for almost $1.6 million to settle that case, something a member of Parliament quizzed him on in July.
"When you signed off the Taylor payment did you see or were you made aware of the 'For Neville' e-mail, the transcript of the hacked voicemail message?" asked Labour MP Tom Watson, who has played a lead role in the investigation.
"No, no, I was not aware of that at the time," James Murdoch responded.
But now, a letter released Tuesday by Parliament contradicts James Murdoch's testimony. In it, Tom Crone, a former lawyer for News International, says Murdoch was indeed aware of the "For Neville" e-mail. "I have no doubt," Crone's letter reads, "that I informed Mr. Murdoch of its existence, what it was and where it came from."
However, in an August 11, 2011, letter to John Whittingdale, head of the Culture, Media and Sport Committee, James Murdoch denies remembering the reported incident. "Let me reiterate that I have no recollection of any mention of 'Thurlbeck' or a 'for Neville' email," it says.
Now, James Murdoch may have to elaborate further in a second appearance before Parliament.
"It's highly likely that James Murdoch will be brought back to give evidence," Watson told CNN. "But before that, we want to take a very detailed account of what the former editor and former lawyer knew. We've moved from the exposure to the second phase -- the very details of the cover-up."
Watson's view was supported by Whittingdale, whose committee has been investigating allegations of widespread phone hacking by British newspapers. He said it was "likely" that James Murdoch would be asked to appear again before his committee.
A second letter appears to show more evidence of a cover-up. Former Royal Correspondent Clive Goodman sent a letter in 2007 to the director of News International's Human Resources Department after Goodman was released from jail for phone hacking the royal family and after he had received a notice of termination of employment.
Two copies were sent to the Parliament - one version from News International and another from News International's law firm, Harbottle & Lewis. The copy from News International redacts more than does the copy from the company's law firm.
In comments that were blacked out of the News International copy but left legible in the lawyers' copy, Goodman says "phone hacking was widely discussed in the News of the World daily editorial conference, until explicit reference to it was banned by the Editor."
That statement appears to undermine a comment from then-Editor Andy Coulson, who told a parliamentary committee in 2009: "I neither knew about phone hacking nor condoned its use."
It's also a further blow to Prime Minister David Cameron, who went on to hire Coulson as his communications director, a post Coulson resigned this year.
In his letter, Goodman asserts that he won promises from the company as he faced jail time.
Goodman says in the letter that he was "promised on many occasions that I could come back to a job at the newspaper if I did not implicate the paper or any of its staff in my mitigation plea. I did not, and expect the paper to honour its promise to me."
For lawyers representing phone hacking victims, the letter may be crucial evidence.
"He pleaded guilty to something on the basis he didn't implicate others at the News of the World, and it was payback time for him," lawyer Mark Lewis told CNN.
The more revelations that emerge about the scandal, the more precarious may be James Murdoch's position as chief executive of News International.
Commenting Tuesday on the evidence from the Culture, Media and Sport Committee, a News International spokesperson cited the board of parent company News Corp. "News Corporation's board has set up a Management and Standards Committee, chaired by independent Chairman Lord Grabiner, which is cooperating fully with the Metropolitan Police and is facilitating their investigation into illegal voicemail interception at the News of the World and related issues.
"We recognize the seriousness of materials disclosed to the police and Parliament and are committed to working in a constructive and open way with all the relevant authorities."