Red Bull boss Christian Horner on Saturday (NZ time) dismissed as idle gossip reports his team spent more than allowed last year and said the Formula One championship leaders were confident in their figures.
Mercedes rival Toto Wolff claimed however that Red Bull had been under investigation for months and it was an open secret in the paddock that one team was in massive breach of the budget cap.
"Maybe he doesn't speak to his CFO," the Austrian told Sky Sports television.
Horner told the broadcaster earlier at the Singapore Grand Prix that none of the 10 teams had so far received a compliance certificate.
"There's an awful lot of rumours and gossip and we know where most of that permeates from," he said, without naming anyone.
"There's a lot of conjecture about Red Bull but that could well be about four or five teams in the pitlane."
According to media reports, Red Bull and Aston Martin exceeded the mandatory US$145 million (NZ$257.4m) budget cap imposed on each team in 2021.
An Aston Martin spokesperson said the team were "in discussion with the FIA, and we are awaiting certification (of the data)."
There was no official confirmation of any breach, with the governing FIA saying it was still assessing the financial data submitted by teams and would proceed according to the rules.
Horner said certificates were due to be issued next Wednesday, although the date had been changed three times already.
"They are following their process. Let them do their process and then let's see what comes out. Anything before that is just speculation," he said.
"It's the first year of these regulations, accounts were submitted in March. There's been clarifications since March on certain aspects of what and how things can be submitted and these regulations are still very, very immature.
"They (the FIA) are taking their time to do the job properly and we're very confident in the submission that we've made. So I wouldn't listen to too many idle bits of gossip and rumour."
Wolff, whose seven times world champion Lewis Hamilton fought Red Bull's Max Verstappen to the last lap of the final race in 2021, said at least two teams were in the spotlight.
"As far as we understand there is a team in minor breach, which is more procedural, and another team that is fundamental and massively over," he said.
"The rumour mill is going since a while that they are over and they are quite a lot over."
Formula One introduced the budget cap last year, narrowing it to US$140m (NZ$248m) this year and US$135m (NZ$239m) next season, to rein in runaway spending by the biggest teams and level the playing field.
Possible sanctions range from fines to exclusion from the championship.
Williams were fined $25,000 this year for a procedural breach of the financial regulations after missing a deadline to submit their accounts.
Red Bull finished second behind Mercedes in the constructors' standings last season.
Meanwhile, seven times Formula One champion Lewis Hamilton, hunting for his first win of the season, pipped championship leader Verstappen to the fastest time in Saturday's opening practice session for the Singapore Grand Prix.
The Briton, topping a session for the first time this year, lapped the 5km Marina Bay circuit in one minute 43.033 seconds, with Verstappen, celebrating his 25th birthday, 0.084 seconds adrift in his Red Bull.
Monegasque Charles Leclerc in his Ferrari was third.
Verstappen goes into Sunday's floodlit Singapore spectacular, back on the calendar after a two-year COVID-19 induced absence, with his first shot at wrapping up a second successive title.
Reuters.
