The Olympic Delivery Authority has declined to respond to claims that there will be a £2bn shortfall for the 2012 Games.

ODA chief executive David Higgins last week hinted to The Observer that the Olympic site would need substantial investment in infrastructure to deliver a legacy of 35,000 homes after the Games.

He said Milton Keynes' 15,000 homes had required £1.5bn of investment, leading The Observer to conclude that the Olympics would need more than £3bn. So far, only £1bn has been earmarked.

But an ODA spokesperson said it was not possible to comment until Higgins' review of all projects had been completed. He added: "David didn't give that number in the interview."