Christian Horner insists he is "calm" in the face of rumours Red Bull could be at the centre of one of the greatest Formula 1 scandals in recent history.
Following widespread media reports from the Singapore paddock, the sport's governing body has now admitted that "alleged breaches" of the budget cap provisions from 2021 are being looked into.
The reports allege that two teams - believed to be Red Bull and Aston Martin - each deliberately spent more than the allowed $140-plus million last year.
Red Bull's transgression is supposedly the most severe.
"Five million in the gray area - that's a massively heavyweight issue," Mercedes boss Toto Wolff told the Austrian broadcaster ORF.
He thinks penalties are inevitable.
"I do believe that something will happen," said Wolff. "The only question is to what extent.
"But it's up to the judges to decide. I wouldn't want to be in their shoes as the consequences affect three seasons at once."
Horner, who shares an acrimonious historical relationship with Wolff, dismissed the story as "just rumours".
"If I listened to every rumour, I wouldn't sleep," he told Sky Italia. "We're an easy team to point the finger at but we are calm.
"We must remember that these are just rumours and we are interested in the facts. It was the first year of the budget cap and I am aware that the results of the investigation will be published, but we are calm," Horner added.
Wolff rejected those comments.
"It's funny to hear that from Christian because they've been under investigation for more than a week or a month. He should be talking to his CFO," said the Austrian.
"All of our reports have been scrutinised and we understand that one team is currently under investigation for a minor violation and the other for a major violation. It's no secret to anyone in the paddock."
Ferrari sporting director Laurent Mekies confirms Wolff's suggestion that the allegations of two teams having breached the rules is "no secret".
"We regard this as a serious incident and look forward to an exemplary resolution of the situation from the FIA," he said.
Bosses for Alpine, Alfa Romeo, Williams and Haas also spoke out about the seriousness of the allegations against Red Bull and Aston Martin.
"They say they understood some things of the regulation differently, so first of all they must clarify this aspect," Haas boss Gunther Steiner said.
"I'm not saying they must be disqualified, but at least a penalty. But I do not know the elements in detail."
Aston Martin, for now, is staying relatively quiet.
"We have submitted our 2021 reporting, we are in discussion with the FIA and we are awaiting certification," a spokesman said.
Dr Helmut Marko, though, insists that Red Bull is "not particularly worried at the moment".
"There are discussions taking place in which certain points are being clarified," he told Sky Deutschland.
"There are people listed who work in other companies - Red Bull Advanced Technologies, Red Bull Technology, Red Bull Powertrains. The only surprising thing is that this has been made public.
"The FIA says it does not know how it was possible that it became public, but it is damaging our reputation," Marko insisted.
