Bernie Ecclestone has defended Ferrari amid accusations of cheating.
Max Verstappen made the "cheating" claim explicit recently, but there is no doubt the FIA is now responding to questions about the legality of the Italian team's power unit.
"I prefer not to comment further," Red Bull-Honda driver Verstappen told Sport Bild.
"I am looking forward to the last race of the season and it's good that the FIA is now on top of these issues," he added.
Verstappen's boss Christian Horner suggested that Ferrari's surge in form this year is, at the very least, suspicious.
"It's pretty difficult to understand," the Red Bull boss told Auto Motor und Sport.
"The three other engines have really moved closer together - only Ferrari stood out with a huge lead. You cannot catch up like that over a winter.
"For two races now Ferrari's lead on the straights has shrunk for whatever reason, and everybody can have their own opinion about that," Horner added.
Former F1 supremo Ecclestone said these sorts of accusations are nothing new.
"I don't believe Ferrari cheated," he told La Gazzetta dello Sport.
"It's always the same in Formula 1. If a team is faster than the others, then the ones who are losing suspect the winning team of cheating.
"It's always been like that," the 89-year-old added.
Ecclestone thinks part of the reason for the current furore is that F1 is missing Charlie Whiting, who died suddenly in March.
He said some teams have always managed to find an advantage by interpreting the regulations more intelligently than their rivals.
"Teams used to do that but then Charlie was on top of it," said Ecclestone. "He was always very good at anticipating things like that."
