FIA president Jean Todt has robustly defended his decision to reach a 'secret deal' with Ferrari over the legality of the team's 2019 power unit.
The governing body revealed at the end of February that it had "reached a settlement" with the team over issues surrounding the fuel-flow rate in last year's Ferrari engines used by the works team, Alfa Romeo and Haas.
But rival teams were upset that the details have been kept confidential, and that there has been no public confirmation that Ferrari actually broke the rules. A letter from all seven non-Ferrari affiliated teams demanded more details and answers.
The teams raised a number of questions in a lengthy submission that gave Todt and Formula 1 CEO Chase Carey five days to respond, which they have now done.
"Three options were available," Todt explained, according to the Daily Mail newspaper. "Closing the case, bringing the matter before the International Tribunal, or entering into a settlement.
"Such decisions fall to the president of the FIA, in accordance with the FIA judicial and disciplinary rules.
"The president informed and consulted with several other key FIA officials as well as the Formula 1 CEO with the objective of building a consensus on how best to address the case.
"He solicited and received recommendations from the FIA technical, legal and financial teams and also took advice from an external experienced attorney."
For his part, Carey himself somewhat distanced himself from the decision, saying that neither he nor his colleagues at Liberty Media had played any part in the investigation. However he stated he was broadly in support of the FIA's approach to the issue
A former Ferrari team principal during the Schumacher championship years, Todt agreed that the FIA was "not fully satisfied" that the Scuderia's engine had been legal "at all times" last season.
But he said that the complexity of the systems involved had made it impossible to prove beyond doubt that Ferrari had transgressed the rules. He added that the terms of the settlement with Ferrari meant the FIA could not release further details with the team's permission.
A new sealed fuel-flow sensor has been added to this year's technical regulations in an attempt to ensure the same potential loophole cannot be exploited again in the future.
But that has done little to assuage the anger of the other teams in the paddock. The newspaper reports one anonymous team member as demanding: "If they can't regulate the sport technically, is the FIA fit for purpose?"