Aston Martin's Sebastian Vettel has been disqualified after finishing second in the Hungarian Grand Prix.
Officials were unable to take the mandatory one-litre sample of fuel from Vettel's car after the race.
The decision would promote Mercedes' Lewis Hamilton to second place and extend his championship lead over Red Bull's Max Verstappen to eight points.
But, unconventionally, for the time being Vettel has been left in the final results pending the appeal outcome.
Governing body the FIA said it was possible to pump out only 0.3 litres from Vettel's car, and that it was no defence to claim no performance advantage was obtained.
F1 rules dictate teams must ensure a one-litre sample of fuel can be taken from the car at any time during the event.
Running less fuel can give a performance advantage as each 1kg of fuel equates to an average of about 0.035secs a lap.
Hungarian Grand Prix stewards said: "The team was given several opportunities to attempt to remove the required amount of fuel from the tank, however it was only possible to pump 0.3 litres out."
Team principal Otmar Szafnauer and technical director Andrew Green said there was 1.44 litres left in the car, but they were unable to extract that much.
https://www.bbc.com/sport/formula1/58050375