Pirelli completes Vettel investigation

Four-time world champion Vettel described Pirelli's performance as "unacceptable" in the wake of his 200mph accident on the penultimate lap of the race at Spa.

Ferrari was attempting a one-stop strategy, with Vettel changing from softs to mediums on lap 14 and then running to the finish on lap 43.

But the German's right-rear tyre failed when he was fending off the Lotus of Romain Grosjean for third place.

Ahead of the Italian Grand Prix, where the tyre compounds will be a step softer this year with the medium and soft in use, Pirelli chief Paul Hembery said: "We have finalised the investigation into Sebastian Vettel's tyre at Spa.

"Detailed conclusions from the technical analysis will be presented at Monza."

In the wake of the Belgian GP, Hembery said Vettel's incident was down to wear, adding he was "surprised" Ferrari tried to do one stop when every other team did two or three.

It followed a high-speed blow out for Mercedes' Nico Rosberg during second practice, with the German demanding rapid action from Pirelli before Monza.