After several days of investigation the cause of Sebastian Vettel's puncture on the opening lap of the Abu Dhabi Grand Prix remains a mystery.

A brief statement issued by Pirelli this morning reads:

"Following an extensive investigation of the circumstances that led to Sebastian Vettel's right-rear tyre suddenly deflating on the opening lap of the Abu Dhabi Grand Prix, a structural failure of the tyre has been ruled out as the cause by Pirelli's engineers.

The tyre in question was a part of a set of P Zero Yellow softs that the Red Bull Racing driver had used to qualify on pole the day before.

Following the incident at the first corner, Vettel completed a lap in order to return to the pits, during which the flapping rubber caused damage to the bodywork and running gear, forcing the world champion into his first retirement of the year.

Although not much remained of the tyre afterwards, there was enough for Pirelli's engineers to carry out a full investigation, in collaboration with Red Bull Racing. Having subjected the tyre to minute analysis, structural failure of the tyre or valve has been ruled out as a cause of the incident. Track debris or other outside circumstances cannot be excluded as a possible cause.

"We can confirm that a structural failure was not the cause of Sebastian Vettel's deflation in Abu Dhabi," said Pirelli' motorsport director Paul Hembery, "a conclusion that we have arrived at together with Red Bull Racing following a detailed examination and analysis of the remains of the tyre. We cannot rule out debris on the track causing damage to the tyre, which then provoked a deflation, but having looked at the track closely there is no direct evidence of this."