The FIA has responded to a statement signed by seven of Formula 1's 10 teams following a private settlement made with Ferrari over their engine.

Last Friday, the governing body made it known publicly that a settlement had been agreed with the Italian team following a technical investigation into the power unit they used last season.

This came after Mercedes and Red Bull had called for clarifications over the policing of fuel flow limits during the second half of last year, amid suspicions Ferrari had found a way to circumvent the FIA sensors.

In the statement announcing the settlement, the FIA did not confirm or deny any decision on whether their engine was legal and the private nature of their conclusion led to the calls for "full and proper disclosure" from the seven non-Ferrari linked teams with the possibility of legal action.

To try and quell that unhappiness, the governing body has now stated that while they too had suspicions the Ferrari engine was illegal, the "complexity of the matter and the material impossibility to provide the unequivocal evidence of a breach" meant their investigation would be unable to end with a "conclusive case".

Therefore, with Ferrari continuing to maintain their innocence and likely to take legal action of their own if the FIA ruled otherwise, the settlement was made.

"To avoid the negative consequences that a long litigation would entail, especially in light of the uncertainty of the outcome of such litigations, and in the best interest of the Championship and of its stakeholders, the FIA, in compliance with Article 4 (ii) of its Judicial and Disciplinary Rules (JDR), decided to enter into an effective and dissuasive settlement agreement with Ferrari to terminate the proceedings," their statement continued.

"This type of agreement is a legal tool recognised as an essential component of any disciplinary system and is used by many public authorities and other sport federations in the handling of disputes.

"The confidentiality of the terms of the settlement agreement is provided for by Article 4 (vi) of the JDR."

The statement then concluded with this guarantee, after the seven other teams has questioned the FIA's ability to govern F1 with "integrity and transparency".

"The FIA will take all necessary action to protect the sport and its role and reputation as the regulator of the FIA Formula One World Championship," it said.

Still, it appears this matter could be some way from being over with Red Bull's Helmut Marko reportedly wanting Ferrari to be punished.

“The behaviour of the FIA is the real scandal,” he said via SpeedWeek.

“We should actually have instructed Red Bull Racing team boss Christian Horner to sue for $24 million in prize money that we would have been awarded for second place in the Constructors’ Championship if Ferrari had been punished accordingly.

“It is unbelievable what is written of an agreement.”

Marko also revealed the instigator of the seven-team response was Mercedes boss Toto Wolff.

“This time we joined the campaign initiated by Mercedes,” he said. “In the future, however, we will think about our own ways to get our rights.”