FIA: BMW, Williams fuel outside rules

As the race stewards continue to investigate the matter to decide on whether or not a punishment is necessary, a statement issued by technical delegate Jo Bauer revealed the extent of the temperature variation of the cars involved.

Article 6.5.5 of the Formula One technical regulations states: "No fuel on board the car may be more than ten degrees centigrade below ambient temperature."

The statement issued by Bauer showed that Heidfeld's fuel was 13 degrees centigrade lower than ambient at his first stop and 12 degrees centigrade lower at his second stop.

Robert Kubica's fuel varied by 14 degrees, 13 degrees and 13 degrees at his three stops; Nico Rosberg's fuel was 13 degrees and 12 degrees out at his two stops and Kazuki Nakajima's was 12 degrees out at his first stop. His second stop was inside the 10-degree limit.

Spyker technical chief Mike Gascoyne said he believed the variation would have provided a performance advantage.

"It can be five to ten horsepower easily," he told autosport.com. "The car is producing a performance advantage during the race. If they dump fuel in that is below the limit, it is an illegal performance advantage. They should be excluded from the event, there is absolutely no doubt."

The implications of a disqualification for the BMW and Williams drivers would be huge, as it could potentially move Lewis Hamilton up the order into fourth place.

In such a case, Hamilton would be crowned the world championship.