Red Bull has been found to have breached Formula 1's spending rules for Max Verstappen's first drivers' championship crown.
The sport's governing body, the FIA, announced on Tuesday morning AEDT that Red Bull was the only team to breach the cost cap that was introduced in 2021.
Red Bull's Verstappen won his first drivers' championship in 2021, overtaking Mercedes rival Lewis Hamilton on the last lap of the final race to win the title.
On Tuesday, the FIA said Red Bull had committed a "minor financial overspend" in 2021, meaning their expenditure was less than 5 per cent over the cap.
Aston Martin was found to have had a procedural issue with submitting their paperwork, but they did not overspend.
"The FIA Cost Cap Administration is currently determining the appropriate course of action to be taken under the Financial Regulations with respect to Aston Martin and Red Bull and further information will be communicated in compliance with the Regulations."
A cost cap of $US145 million ($230m) was introduced last year as F1 tried to become more financially sustainable.
Red Bull issued a statement after the breach announcement saying their paperwork submission — which was handed to the FIA in March — was under the cap in their opinion.
"Our 2021 submission was below the cost cap limit, so we need to carefully review the FIA's findings as our belief remains that the relevant costs are under the 2021 cost cap amount,' they said.
"Despite the conjecture and positioning of others, there is of course a process under the regulations with the FIA which we will respectfully follow while we consider all the options available to us."
Consequences for this breach can include "financial penalties and/or minor sporting penalties could be imposed".
This could include Red Bull being stripped of points from last season.
Mercedes and Red Bull had a historic fight for the drivers' championship in 2021, with Red Bull's Verstappen overtaking Lewis Hamilton on the final lap of the Abu Dhabi Grand Prix to win the title.
Procedural issues under a late safety car which allowed the final lap to be raced under a green flag is still a source of debate among fans.
Then-race director Michael Masi was removed from his role in the aftermath of the controversial season finale.
What is F1's cost cap?
F1 introduced a cost cap for teams' expenditures last season of $US145 million.
The cap was first announced in 2019 and was introduced to shrink the gap between the top teams and the backmarkers on the grid.
The cap has shrunk to $US140 million for this season and $US135 million for 2023.
The cap covers expenditure that relates to car performance.
Marketing costs, race driver fees and the salaries of the team's three highest-paid personnel are not included in the cost cap.
Other things which are excluded are travel expenditures for race and testing weekends, fees to enter the championship and purchasing superlicences.
What are the penalties for breaching the cap?
The FIA has two levels of cap breaches — minor and major.
A minor breach is a team going less than 5 per cent over the cap, while a major breach is considered a team exceeding the cap by more than 5 per cent.
The penalties for a breach are not set in stone, with a variety of options available to the F1 hierarchy.
Less-serious penalties could include a fine or a reduction in their cap for the following seasons.
But teams could potentially be stripped of competition points.
The FIA lists these as possible punishments for a minor breach of the cap:
- Fine
- Public reprimand
- Deduction of constructors' championship points awarded for the championship that took place within the reporting period of the breach
- Deduction of drivers' championship points awarded for the championship that took place within the reporting period of the breach
- suspension from one or more stages of a competition or competitions, excluding for the avoidance of doubt the race itself
- Limitations on ability to conduct aerodynamic or other Testing
- Reduction of the cost cap
The FIA has not announced what penalties Red Bull will face.
Rumours of Red Bull's overspending circled
The FIA was supposed to certify the costings of the teams last week but announced it would be delayed until now.
In the lead-up to the scheduled certification, rumours surfaced that two teams — Red Bull and Aston Martin — had exceeded the $US145 million cap.
The issue was the main talking point during the Singapore Grand Prix weekend in the paddock, with team bosses at Mercedes and Ferrari saying a breach from Red Bull should be punished harshly.
Mercedes boss Toto Wolff described Red Bull's alleged investigation of overspending as an "open secret" while talking to the UK's Sky Sports F1.
"All of us have been investigated diligently and, as far as we understand, there is a team is in minor breach, which is more procedural, and another team that is fundamentally massively over and that is still being looked after," he said.
"That is an open secret in the paddock."