The FIA has ended its investigation into Ferrari’s use of its energy recovery system (ERS) on its SF71H Formula 1 car after being “satisfied” by its findings over the Monaco Grand Prix weekend.

It emerged on Thursday that the FIA had fitted a new piece of hardware to Ferrari’s ERS during practice in Monaco following questions raised about its usage amid suggestions the Italian team had found a way to exceed the maximum permitted energy usage.

Bosses from rival teams Red Bull and Mercedes welcomed the investigation, but FIA race director Charlie Whiting confirmed on Saturday that F1’s governing body had been “satisfied” by its findings, bringing its investigation to a close.

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“We had some concerns in Baku that were difficult to explain and we worked through it with them,” Whiting said in a media briefing attended by both Reuters and The Mail on Sunday in Monaco.

“In Spain, Ferrari showed us things that helped satisfy us that they were inside the rules. We first looked at data, digging quite deep. We had to understand whether Ferrari’s explanations were valid.

“We were never in doubt that things were above board, but by Friday night we were convinced. We have some pretty clever guys working for us now to spot this kind of thing.

“It is the duty of the competitor to satisfy the FIA that their car complies at all times and they were having difficulty satisfying us. Here, we are now satisfied.”

Whiting went on to explain how the issue had escalated following speculation through the F1 paddock, but called the allegations against Ferrari “unsubstantiated”.

“It came from a Ferrari engine man now at Mercedes, but his information would be the length of his gardening leave old,” Whiting said.

Vettel will start Sunday’s Monaco Grand Prix from P2 on the grid behind Red Bull’s Daniel Ricciardo, with Mercedes’ Lewis Hamilton set to line up third.