Former BBC boss Mark Thompson has apologised for the corporation's failed Digital Media Initiative (DMI) which was scrapped at the cost of nearly £100m of licence fee-payers' money.
The project, to create an integrated digital production and archiving system, was abandoned in May 2013.
Asked about previous evidence, where he said DMI was working well, Mr Thompson told the Public Affairs Committee: "I don't believe I have misled you on any other matter and I don't believe I misled you knowingly on this one."
He said it "failed as a project" and added that he "wanted to say sorry" for the waste of public money.
But he told MPs his previous evidence was "a faithful and accurate account of my understanding of the project at that point".
A report by the National Audit Office said the BBC Executive "did not have sufficient grip" on the IT project and did not properly assess the system to see whether it was "technically sound".
BBC bosses - past and present - argued over who knew what and when about huge payoffs to senior staff as they gave evidence to MPs today.Read the full story ›
This was an attempt by MPs to try and work out why all the money that taxpayers pay in the licence fee was going - some of it to BBC bosses who were leaving.
I'm not sure they did get to the bottom of it because what we had was seven executives falling over themselves to insist they did not know about this, and that they weren't involved in things that other people said they were involved in.
Asign perhaps of the bitterness, when one BBC journalist tweeted that the BBCnewsroom had cheered at the exchange when the human resources boss was told off about 'lies'.
The MP Margaret Hodge, who chairs the Public Accounts Committee, said this was an unedifying occasion forthe BBC that had served only to damage it and I think it will make thegovernment look again at how the BBC is regulated.
Seven BBC executives - past and present - argued over who knew what and when about huge pay-offs to senior staff, as they appeared in front of the Public Accounts Committee today.
Former director-general Mark Thompson, was forced to deny a charge that the BBC had "lost the plot" when it agreed a pay-off of almost £1 million to his former deputy, Mark Byford.
ITV News' UK editor Lucy Manning reports.
The chair of the Public Accounts Committee Margaret Hodge has described the questioning of BBC executives as an "unedifying occasion which can only damage the standing and the reputation of the BBC".
Current and former BBC executives were questioned by members of the committee today in the wake of controversy over large payoffs to corporation executives.
Ms Hodge said: "At best what we've seen is incompetence, lack of central control, a failure to communicate for a broadcaster whose job is communicating.
"At worst we may have seen people covering their backs by being less than open. That is not good."
The chairman of the BBC Trust said there was "a cultural issue" of high pay that had to be dealt with and he apologised for.
Lord Patten said:
The best cultural director in the world, Neil MacGregor, got £180,000 a year for running the British Museum. How many people at the BBC get paid more than that and how can we justify that?
Licence fee payers will be "dismayed" by the evidence given by BBC executives past and present about massive payoffs to staff, a senior Labour MP warned.
Harriet Harman MP, shadow culture secretary, said: “Clearly the interests of the licence fee payers were not properly protected and there was a failure of governance.
"The Charter renewal process, and the debate around it, will be the opportunity to re-examine those governance issues."
Committee member Chris Heaton-Harris compared the meeting to a fairground game, saying it was "the most bizarre game of whack-a-mole I've ever seen in my life, where you hit one fact down and it throws up other questions".
Turning to the witnesses, he said: "I just wonder if one of you would like to take responsibility for this?"
Committee chair Margaret Hodge told Sir Michael Lyons, former chairman of the BBC Trust: "You could have done it for less, that's the whole premise for us."
He replied: "I have heard your message but I am not personally convinced that's the case. My judgment tends towards that of the Director General here."
He said that it was a way of doing things that prevented "disruption" to BBC services and projects that were in the pipeline.
The former Director General of the BBC told the Commons Public Accounts Committee that he believed Mark Byford's severance package represented "value for money".
Mark Thompson also said he stood by his claim that the committee had been misled when they were told the Trust had been "kept in the dark" about severance packages.