Mercedes under investigation over high tyre pressures

Driver Lewis Hamilton and his Mercedes team-mate Nico Rosberg are under investigation by the stewards for a potential breach of the regulations regarding minimum starting tyre pressures during the Italian Grand Prix here on Sunday.

Hamilton won the race, beating Ferrari's Sebastian Vettel, with Felipe Massa finishing third for Williams. Force India were sixth and seventh, courtesy Sergio Perez and Nico Hulkenberg, respectively.

Hamilton also extended his championship lead over Nico Rosberg to 53 points, after his team-mate was forced to retire whilst running third just two laps from home, the rear of his car on fire, reports formula1.com.

Guidelines issued by tyre maker Pirelli stated that teams must start the race with tyre pressures of 19.5 pounds per square inch (psi) or above, however when both Mercedes were checked ahead of the start, Hamilton's left-rear tyre was found to be 0.3psi below the required mark, with the same tyre on Rosberg's car 1.1 psi under, reports formula1.com.

The FIA also checked the starting tyre pressures on both the Ferrari cars, but found them to be above the required value.

Mercedes received the report from the Formula One technical delegate Jo Bauer, before the chequered flag signalling the end of the race had fallen.

The matter is under investigation by the stewards.