The Italian media suspects a whistleblower is behind the bizarre saga surrounding the legality of Ferrari's 2019 engine.

Rival teams are reportedly furious that the FIA reached a secret "settlement" following a lengthy investigation into how the power unit works.

At best, the story is confusing.

"To understand, look outside the FIA," an unnamed team engineer told Italy's Corriere della Sera.

Correspondent Giorgio Terruzzi suspects that "confidential technical information" flowed out of Ferrari to the governing FIA.

He wrote: "It is known that Toto Wolff is a sworn enemy of Ferrari after the veto that was put on any team boss being promoted to the top of Liberty Media.

"Wolff has the character and ambition to try to get what he wants. The FIA statement is ambiguous, of course, but it is necessary to quell a ferocious and even darker conflict."

Leo Turrini, another Italian journalist known to be close to Ferrari, wrote on his Quotidiano blog: "Throughout this story, the FIA has acted as if it had information from - to use an English term - a whistleblower.

"I am not (spy novel author) John le Carre, but I do not think I am wrong," he added.

Many other F1 insiders are predicting that this is just the beginning of what will become a deeper scandal.

"The question of whether Ferrari cheated is almost secondary compared to the problem of transparency that this creates," an unnamed F1 team member told Ouest France newspaper.

"This is not in line with today's world and the demands for transparency in terms of the governance of society and sport, to which the FIA subscribes in its statutes," another insider added.

It is believed several of Ferrari's rivals have asked the FIA for clarification.

"While respecting the confidentiality and legality of the agreements, (the FIA) is open to the queries of teams," AFP news agency quotes an FIA official as saying.