McLaren team principal Eric Boullier has accused Red Bull of using coded radio messages to help Daniel Ricciardo in Sunday's Singapore Grand Prix.
A complicated week in the build-up to the race for the FIA saw them initially issue a detailed list of messages that would be prohibited from the race in Singapore onwards.
Motor sport's world governing body, however, backtracked on several of the guidelines following complaints from teams.
But any form of coaching advice, such as where a driver was losing time, where to brake, how to corner quicker etc, remained banned.
During the race at the Marina Bay Street Circuit, and with Daniel Ricciardo encountering problems with the battery in his car, at one stage he was told: "Avoiding exit kerbs may help the problem with the car."
Boullier feels such a message contravened the new regulations as he said: "We had no issues (with the new radio rules) on our side.
"It just made us more busy listening to others to make sure they made no mistakes, like Red Bull twice with Ricciardo.
"I think it was coded, but it is up to the FIA to investigate. It is not for me to investigate.
"But it was a strange message. Once was okay, but twice, three times? You can doubt what exactly the car problem was."
Red Bull team principal Christian Horner has confirmed discussions were conducted with FIA race director Charlie Whiting during the grand prix to clarify matters.
With Ricciardo going on to finish third, Horner said: "The problem started relatively early, probably before half distance, where we had basically an issue with the battery not discharging.
"There was quite a lot of management that needed to go on to help him with that. It was quite intermittent, the problem we had.
"If there had been a full radio ban it wouldn't have made life easier, that's for sure.
"We spoke to Charlie, we told him he's got some reliability issues and that was why he was told to keep off the kerbs because that was causing damage to the battery for instance.
"It's finding that balance with this radio stuff."