Vettel’s right-rear tyre blew on his Ferrari along the home straight just as the four-time F1 champion started the 27th lap of the race at the Red Bull Ring.
Pirelli initially suggested debris lay behind the blowout to the soft-compound rubber, only to then withdraw from such a finding post-race, instead preferring to await the outcome of an investigation before providing clarification.
Following a full inquiry into the failure, a Pirelli statement said: “Analysis of the tyre issue that affected Sebastian Vettel at the recent Austrian Grand Prix has been concluded and the results shared with Ferrari.
“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.”