The FIA announced in Monaco that its investigations have suggested that the Italian team was doing nothing wrong.

However, rivals have continued to question the recent strong performance of both the works cars and customer teams Haas and Sauber.

"Something is going on there, it's not normal," said Renault's Nico Hulkenberg.

"Since a couple of weekends, since France I think, all Ferrari-powered cars have a lot of power all at once.

"It's difficult for us against Haas, because in the corners we are at eye level or better but on the straights we lose a lot."

Whiting and other key FIA players had a meeting with Mercedes representatives at the team's motorhome in Hockenheim.

"We are entirely satisfied with everything on that front, as we said in Monaco," said Whiting.

"Some teams have been asking further question and we were just there to try and help them have some peace, if you like."

Asked if Mercedes had questions about legality, or just wanted to know where the limits were for its own development, Whiting said: "Again, those discussions are private.

"I don't think I should be telling you. If you want to talk to Mercedes, they'll tell you but I think what goes on behind closed doors should remain behind closed doors."

Mercedes boss Toto Wolff would not be drawn on the discussions, implying that it was a routine gathering.

"The exchange you're having with the FIA and some of the other teams, or engine manufacturers, is on a regular basis," he said.

"It's more visible if you do it on a weekend, on track, in the motorhome, but it's completely regular business to discuss various technical topics."

Renault Sport F1 boss Cyril Abiteboul admitted that the data suggests that Ferrari is doing something "strange" - but he stressed that doesn't necessarily mean that it is illegal.

"First we know we have a power deficit, which up until now was against Mercedes," he told Motorsport.com.

"They are still here but we see indeed that Ferrari has taken the upper hand, so congratulations to Ferrari in that battle, which is more a technical battle, but less visible. The step that they have done is amazing.

"It's a step that they have done to a certain degree that does not go with a hardware introduction, it's also a step that we see across all three teams, not just Ferrari, which is not necessarily a battle for us, but also Haas and Sauber, which are more of a battle for us.

"Clearly we are scratching our heads, because we look in particular at the GPS profile, and we we see indeed that it's really strange what they are doing.

"But doing something strange doesn't mean that it's illegal. I think we must give credit to what they have done, and that should be an extra commitment to work harder, and try and do the same step on our side."