Christian Horner is adamant his Red Bull RB8 is legal despite rivals raising questions about a 'hole' in the car's floor.
On Sunday morning ahead of the Monaco Grand Prix, it emerged that rivals had raised questions about the 'hole', which is found in the surface of the step plane directly in front of the rear tyres.
Under article 3.12.5 of F1's technical rules, cars are not supposed to have any hole in the floor in certain areas.
Horner, though, is adamant that his team's cars are legal and have been cleared by the FIA's stewards.
"There was a bit of a fuss after the Bahrain race but it was clear the car complied," said the Red Bull team boss.
"We sought clarification after that, but there is no doubt the car is fully compliant.
"The car is identical to that which ran in Barcelona and Malaysia as well. There are other cars running in similar situations.
"As I say, we're totally comfortable with the car, that it complies with the regulations and we're not going to change it."
Asked if the FIA agreed with Red Bull, Horner said: "Yes.
"They wouldn't have passed the car in scrutineering, we wouldn't have had a debate and discussions in Barcelona.
"We're certainly comfortable this car is fully compliant."