Lewis Hamilton's victory in the German Grand Prix has been thrown into doubt with the Mercedes driver summoned to see the stewards over a potential breach of the rules for crossing the pit entry line.
The world championship leader cut across the pit entry back on to the track during the late-race safety car period on lap 52, amid a confusing situation about whether to stop again or not.
His actions have now been reported to the stewards and, if he is found guilty of an offence, then he faces a time penalty that could drop him down the order.
Although the FIA's race notes ahead of the Hockenheim weekend did not make specific reference to drivers cutting back on track, the regulation Hamilton is believed to have broken is clear.
FIA International Sporting Code, Appendix L, Chapter 4, Article 4 d) states: "Except in cases of force majeure (accepted as such by the stewards), the crossing, in any direction, of the line separating the pit entry and the track by a car entering the pit lane is prohibited."
Speaking about the situation before the summons, Hamilton said that the late decision to cut back to the track was prompted by the fact that he was trying to do the opposite to race leader Kimi Raikkonen.
"It was so confusing," said Hamilton. "We came around Turn 16, and Kimi started turning in, they had asked me to box, and I said Kimi is pitting.
"Then they said 'stay out'. I was already in the lane and then I started turning out to go over the grass.
"Then they said 'no stay in', but I was already back on track.
"The reason I mention it is that there are times when you do the opposite to the car in front and I felt this was a chance to do the opposite to Kimi and gain ground on the road.
"That is why I questioned it and ultimately it turned out to be the right thing.
"But it was so intense and really confusing - because they were all panicking on the pit wall and I was probably the only relaxed one."