FIA race director Charlie Whiting has claimed poor welding was responsible for the drain cover which came loose and caused Romain Grosjean to crash, leading to the abandonment of Practice 2 at the Malaysian Grand Prix.

The Haas driver claims he was unsighted after his right-rear tyre exploded upon impact with the metal cover, which was lifted by the force of Valtteri Bottas' Mercedes driving over it on the exit kerb of Turn 12, and sent the Frenchman spinning into the wall on the outside.

“I’m fine, that’s the most important thing,” said Grosjean when asked how he was following a trip to the medical centre following an impact recorded at 17G.

More typically drain covers can be dislodged on street circuits or at new venues, meaning the incident on Friday came as quite a surprise to many on a track which has hosted F1 since 1999, albeit saw a new lap record set on Friday by the faster 2017 cars.

"There are quite a few of them around the circuit and at this particular place, there are five at intervals on the outside of T12," Whiting told Autosport explaining what occurred.

"That's a high-G corner with a massive load being put through, and what we have found is some of these drains are bolted down and some are welded down and welding is perfectly acceptable.

"I suspect the bolts which have been going into little sort of lugs on the receptacle, which is where the water goes, have probably broken and rather than replace the whole thing, they've thought, we'll weld it down.

"Quite evidently, the welds just gave up. It's as simple as that really. No one saw that coming."

A full inspection of all drains will now take place and those which are welded will be re-welded in time for Practice 3 on Saturday.

As for Haas, they have been given special dispensation by the FIA to ignore the curfew usually imposed on team personnel at every race, in order to fix Grosjean's car.

Though teams are allowed to break curfew twice without penalty, this will not count towards that as the governing body see what occurred as an exceptional circumstance in which the team and the driver were not responsible.