Monza, Italy - F1 teams were sternly warned before the 2015 Italian grand prix to adhere to Pirelli's new tyre pressure guidelines.
At the end of Sunday's (September 6) race it became clear that the result was under scrutiny and expected to remain unconfirmed until the outcome of a stewards' inquiry into the starting pressures and temperatures of the Mercedes cars.
Cuts discovered in tyres
Read: 2015 Italian GP: As it happened
After a two hour wait, the FIA finally announced that Hamilton can keep his win.
After the blowout saga of Spa-Francorchamps, and the threat of Lewis Hamilton's disqualification at Monza, it emerges that Pirelli also discovered cuts in its tyres in practice and qualifying before the Italian GP.
Tyre damaged by glass
Paul Hembery said before the race: "In one case, the tyre was damaged by broken glass."
Germany's Auto Motor und Sport reports that Pirelli subsequently called on the FIA for assistance to enforce its rules, with "harsh penalties" to await those who push their luck.
Correspondent Michael Schmidt said: "The stewards already acted in GP2, Canamasas and Evans were put to the back of the grid for being below the limit."