Oct.22 (GMM) A cloud still hangs over Kimi Raikkonen's world championship, despite stewards not penalising a trio of cars after the Brazilian grand prix.

Nico Rosberg's Williams and the two BMW-Saubers, which placed fourth to sixth at Interlagos, were found by post-race scrutineers to have been using fuel that was more than 10 degrees below ambient temperatures -- a clear breach of the rules.

But stewards said they could not apply penalties due to discrepancies between official temperature figures provided separately by the FIA, Formula One Management, and travelling meteorologist Meteo France.

A statement said it would therefore be "inappropriate" to penalise the cars.

If two or more of the cars had been excluded, seventh placed Lewis Hamilton would have moved up to the requisite fifth place for him to be declared world champion ahead of Ferrari's Raikkonen.

In light of the technical delegate's belief that the three cars were using illegally cold fuel, Hamilton's team McLaren has appealed the stewards' decision.