Lewis Hamilton's Italian Grand Prix victory has been put under investigation by the stewards to determine whether his Mercedes car broke tyre pressure rules.
The 30-year-old cruised to a relatively straightforward first-place finish in Monza, but with five laps to go his engineers told him to speed up, offering no explanation.
Jo Bauer, the FIA's technical delegate, told reporters: "The measured minimum tyre starting pressure of the left-hand rear tyre of car 44 (Hamilton's) was 0.3 PSI below the specified minimum tyre starting pressure... I am referring this matter to the stewards for their consideration."
Teammate Nico Rosberg, who retired from the race with engine failure, has also seen his car come under investigation for being 1.1 PSI below the minimum tyre starting pressure.
