Pirelli says initial analysis of Ferrari's tyres after the British Grand Prix showed that Kimi Raikkonen and Sebastian Vettel's failures were caused by totally different issues.
Ferrari suffered a double blow in the closing stages of the Silverstone race when both Raikkonen and Vettel were forced to pit with tyre problems.
Raikkonen's tyre tread appeared to come apart on lap 49, while Vettel suffered a total failure one lap later. The incidents meant Raikkonen dropped to third, while Vettel slipped to seventh.
Pirelli has begun an immediate investigation into what happened, but said its first examination of the rubber suggests that the two incidents were not caused by the same problem.
"We are obviously investigating the tyres as usual but more deeply considering what happened," said Pirelli boss Mario Isola. "We believe but it has to be proven that the model failure of the two tyres is different. So we need to investigate.
"What we can exclude that we had any carcass failure on Kimi’s tyres because the tyre was still inflated. There is a part of the tyre that is damaged and we will investigate deeply on all the tyre and not only this tyre.
"Sebastian had a different issue with a loss of air, so we have to understand. We will provide a report.
"We are working together with the team because the data from the teams are an important part of the investigation and we are working already with them to better understand that it is in the interests of everybody to work out what happened and that is all."
Raikkonen's issue was caused by the tread of his tyre coming away, with the tyre not actually losing any air as he returned to the pits.
Vettel, on the other hand, suffered a puncture. Pirelli is examining whether a lock-up that Vettel had a few laps beforehand, as he battled Valtteri Bottas, could have contributed to the problem.
Ferrari admitted it had been caught by surprise over the problems, although it was clear both its driver were pushing hard at the end while race leader Lewis Hamilton was able to back off in the closing stages to manage a small blister he had suffered.
Vettel said: "Hindsight is great, with hindsight it is easy, but at the time it felt okay. Kimi I think had a similar issues, and his tyres were at least five or six laps fresher. So I think it caught us both by surprise.
"I think it could have been a little bit better for sure, but disaster I don't think so. I think we had a good car, especially in the corners. The balance was alright."