Felipe Massa's two punctures during first free practice for the Chinese Grand Prix were caused by an issue with the bodywork on the car, rather than a fundamental tyre problem.
The Brazilian suffered two dramatic left-rear delaminations during the session, the first pitching him into a spin before a second is believed to have left debris collected by Kevin Magnussen, who would suffer his own left-rear blow-out.
Raising concern that the failures were the result of a fundamental Pirelli issue, Massa confirmed to Sky Sports F1
that is seems an issue with the bodywork on the Williams FW38 was the primary cause for the failures.
"We had two punctures. Why, I don't know. We are investigating why we are having this problem. For sure something is touching the tyre or the wheel or whatever. So we need to understand."
Though Massa says thorough checks were undertaken on the car after the first failure, the second problem was indeed identical.
"We had no idea why we have this first problem," he said. "So we checked this car, everything was OK, so we went again. And then we had the same problem again on the out-lap which I was slow so for sure something is touching the tyre which we don't understand why."
Pirelli has since confirmed none of the three failures were caused by problems with the tyre itself.