Pirelli has concluded that Sebastian Vettel's tyre failure in the Austrian Grand Prix was caused by debris.
The German crashed out of the race after his rear right tyre exploded as he was running down the main straight on lap 26 of the Red Bull Ring race.
The Ferrari driver was leading at that point, having stretched his first stint on supersoft tyres.
Despite the long run, Pirelli has dismissed suggestions that the tyre was fatigued, and said it believes the damage was caused by debris on track.
"Analysis of the tyre issue that affected Sebastian Vettel at the recent Austrian Grand Prix has been concluded and the results shared with Ferrari," said Pirelli in a statement.
"The few remaining parts of the tyre in question, together with an in-depth comparison to other tyres used in the race, reveal no signs of fatigue or structural failure in the right-rear tyre itself.
"Consequently, the issue appears to be caused by an item of debris, which led to the breakage of the tyre."