The Public Accounts Committee's 39th report said that the Olympic Delivery Authority failed to include £400m required for an IT system for the planned Olympic Park.
In 2006 it was announced that the cost estimates had increased by some £900m, which included the IT costs.
The report said, "In November 2006 the secretary of state reported to the Culture, Media and Sport Committee that overall the cost estimates for the Olympic Park had increased by some £900 million.
"The increase included some £400 million for IT and site mobilisation and the costs of the CLM Consortium, appointed by the Olympic Delivery Authority as its Delivery Partner to assist in project managing the delivery of the venues and infrastructure. The original budget had used the costs of an urban development corporation as a benchmark for the Olympic Delivery Authority's running costs, with the result that these costs had been seriously underestimated."
At the time of the PAC's examination in March this year, and 20 months after London was awarded the Games, there was still no final budget in place. But on March 15, ten days after their hearing, the secretary of state for culture, media and sport announced a new total budget of £9b.