Raising doubts about the veracity of the phone-hacking account given by Murdoch before the Commons Culture, Media and Sport Committee, his former employees have said they had informed him of a critical piece of evidence in the scandal.
Murdoch, who was quizzed this week, had told the committee that he was not "aware" of an email suggesting the practice went wider than a "rogue" News of the World reporter.
But former NOTW editor Colin Myler and ex-News International legal manager Tom Crone last night said they "did inform" him of the email.
In a statement issued by News Corporation, Murdoch responded by saying: "I stand by my testimony to the select committee".
The testimony in question refers to the April 2008 payment authorised by Murdoch as part of an out-of-court settlement of more than 600,000 pounds to Gordon Taylor, chief executive of the Professional Footballers` Association, over the hacking of his phone.
He said at that time he did not know the full extent of hacking that may have been going on at the tabloid.
The paper`s royal editor Clive Goodman and private investigator Glenn Mulcaire had both been jailed for hacking into phones of the royal household in 2007.
At the committee hearing, Labour`s Tom Watson asked Murdoch: "When you signed off the Taylor payment, did you see or were you made aware of the full" email suggesting hacking was more widespread than had been admitted.
To which, Murdoch replied: "No, I was not aware of that at the time... There was every reason to settle the case, given the likelihood of losing the case and given the damages - we had received counsel - that would be levied".
In their statement, Myler and Crone said: "Just by way of clarification relating to Tuesday`s CMS Select Committee hearing, we would like to point out that James Murdoch`s recollection of what he was told when agreeing to settle the Gordon Taylor litigation was mistaken.
"In fact, we did inform him of the `for Neville` email which had been produced to us by Gordon Taylor`s lawyers".
In an editorial titled `News Corp and phone hacking: Wilful blindness at the very top`, The Guardian said: "If Mr Murdoch`s evidence was wrong, it undermines all the clean broom assurances he and his father gave to parliament on Wednesday. A very great deal hangs on sorting out who is telling the truth".