The BBC's director general, Mark Thompson, disputed the NAO's claim that a Euro 2008 studio cost an extra £250,000. He said that the figure was incorrect, adding that the actual figure should be an "incremental cost" of £50,000.
Thompson and BBC trustee Jeremy Peat were criticised for using private auditors KPMG, rather than the NAO, to audit the BBC's annual accounts.
Also based on the NAO report, and despite repeated questions from committee members, Thompson refused to name the sports presenter who cost 20 per cent of an event's budget.
The BBC said it would identify the presenter in a confidential letter to MPs.