Abt, who won the previous race in Mexico City after a rapid mid-race car swap, was running third when the seatbelt issue occurred at the Uruguayan costal circuit. He came into the pits to get the belts fixed and eventually came home 14th.

“I was completely unbuckled in the car, which I have no clue how it’s even possible,” he said. “This we have to figure out, but of course in that situation what do you do? You risk your life or you come in – for me it’s no choice.

“So I came in, redid the belts, and then we lost too much to gain any points.”

The incident was investigated after the race, but the stewards were satisfied that “after hearing the driver and the team manager and the deputy technical delegate, the stewards consider the driver left the pits after mandatory car change with buckled and tightened seat belts,” according to an FIA bulletin.

The data of the belt tension device on Abt’s two shoulder straps showed that after the pitstop his belts were fixed properly and no further action was taken.

FE’s car swaps have been under intense scrutiny in recent races after the minimum pitstop time was removed ahead of the Santiago event.

“[It was] a real shame,” said Abt. “It was a very good race, I felt very strong, [I] managed to overtake [Oliver] Turvey and then [Alex] Lynn before the pitstop.

“I came in P3, went out P3 – all good, feeling really fast – and then after two laps I realised that my belts basically came loose under braking – all four.”

McNish: Problem was costly for Audi

Audi team principal Allan McNish reckoned the issue cost the team a double podium, as Lucas di Grassi finished second, just behind race winner Jean-Eric Vergne.

“Daniel was looking for a podium as well,” McNish told Motorsport.com. “He went out – it was fine – then they got loose somehow and then he clearly came straight back in to fix them and off he went again and that was it.

“I’ve had that personally before in other championships and you know when it happens and you have to come straight back in. There’s no questions about it. We have to find out what happened.”