A revised budget for the 2012 Olympics will be announced "soon", a top civil servant has told MPs.
The initial estimate for staging the Games was £2.35bn
Jonathan Stephens, permanent secretary of the Department for Culture, Media and Sport, said the need for figures was "recognised... as urgent now".
The comments, to the Commons culture committee, follow reports that the budget for the event could rise to £9bn - from an initial figure of £2.35bn
Committee chairman Edward Leigh called the lack of a new figure "ridiculous".
Mr Stephens told the MPs the review of the overall budget would be "thorough" and this was why the issue was "not yet resolved".
He added: "What the government wants to provide is a final budget.
"It will do so soon. I don't have a date. All I can say is soon."
Mr Stephens also said: "Our aim in this is to keep costs strictly under control."
Mr Leigh, a Conservative MP, said the situation was "a recipe for an open-ended cheque book".
Last month, the BBC discovered that the Treasury and the Department for Culture, Media and Sport were discussing a price of £9bn - up from an initial figure of £2.35bn - for the Games.
David Higgins, chief executive of the Olympic Delivery Authority, told MPs the Games were the "largest ever event occurring in the world outside a reasonable-sized war".
Earlier in the House of Commons, Conservatives accused Chancellor Gordon Brown of "incompetence" and "undermining the credibility" of the 2012 Olympics.
Shadow Culture Secretary Hugo Swire said the chancellor had signed off a budget for the games which was now "two or three times" the original figure.
And he had not produced "an extra penny" for elite athletes, he told MPs.
But Culture Secretary Tessa Jowell said there was "absolutely no substance" in the comments.
In last year's Budget, Mr Brown announced a £600m funding package for athlete training.
Lottery funding would supply £300m, with £200m of public money and £100m coming from private sector sponsorship, it was added.
Mr Swire said the planned sponsorship of £100m had not materialised.
He asked Ms Jowell in the Commons: "What kind of progress is being made in these negotiations, or is it another case of press release politics?"
He also accused the chancellor of "contemplating another raid on the lottery to pay for his incompetence".
But Ms Jowell said: "The plan to raise money for elite sport from the private sector will be negotiated and will be in place when it is ready."