The IOC's co-ordination commission have had little cause for concern over London's preparations previously but the fact that a construction contract has yet to be signed for the Olympic village has raised eyebrows.
Only one firm, Australian contractors Lend Lease, are bidding to the build the village and the Olympic Delivery Authority admit that the "challenging" global economic climate has made agreeing a final contract more difficult.
A source close to the IOC's co-ordination commission said: "The commission will want to be satisfied that construction of the village will proceed on time and as planned.
"It is the biggest project in Olympic Park and the commission will want assurances."
The Government allocated £492 million in their budget to build the village and the international media centres and hope to raise a significant sum from the private sector, but may have to raid their contingency fund to seal a deal.
There is also a source of income from selling the accommodation for 17,320 athletes and officials as 3,000 apartments after the Games.
Negotiations with Lend Lease are covering not just the cash for building the village but the firm's involvement with selling the flats post-2012.
The ODA insist that interim agreements with Lend Lease will allow work on the village to start next month.
An ODA spokesman said: "The Olympic Village site is now clear. Planning applications for the first blocks of the flats have now been submitted and Lend Lease are due to start piling next month.
"We expect to sign interim agreements shortly and aim to have financial arrangements in place before the main build later this year.
"The changing economic situation remains a challenge but we remain on-programme."