The FIA is satisfied Ferrari's 2018 car conforms to Formula One rules amid concerns over the configuration of its energy recovery system.
There had been suggestions among rival teams that the Scuderia could be deriving an advantage from its twin-battery set-up beyond what is permitted within the regulations.
But FIA race director Charlie Whiting insisted the governing body is happy with the explanation provided by the Italian manufacturer.
"We are now satisfied everything is in order," Whiting told The Mail on Sunday.
"The matter was exacerbated by unsubstantiated allegations that went through the paddock like wildfire.
"If we had a hard case, we would have gone to the stewards, but we didn't have anything.
"We had concerns in Baku that we couldn't explain.
"In Spain, Ferrari showed us things that helped satisfy us that they were inside the rules.
"We first looked at data, digging quite deep. We had to understand whether Ferrari's explanations were valid.
"We were never in doubt that things were above board, but by Friday night we were convinced. We have some pretty clever guys working for us now to spot this kind of thing.
"We will probably ask Ferrari to run new hardware at future races to make it easier for us to monitor, but we have a system here in Monaco to establish what is happening without an additional sensor."
Red Bull's Daniel Ricciardo will start on pole in Sunday's Monaco Grand Prix, with Ferrari duo Sebastian Vettel and Kimi Raikkonen second and fourth respectively, either side of Mercedes' world champion Lewis Hamilton.