Red Bull and Mercedes are confident the FIA will come down hard on Ferrari if they are found to be using their ERS illegally.

Thursday’s practice in Monaco saw the Scuderia run an extra sensor and special software as the FIA investigated claims they are using their energy recovery system in an illegal manner.

The allegations claim that the team’s unique battery layout allows Ferrari to bypass the FIA sensor to exceed the 120kW limit that can be deployed by the MGU-K.

Red Bull, though, are confident the FIA’s measures in Monaco will put the matter to rest.

“We’re not an engine supplier, so maybe Toto [Wolff] can answer more on the engine specifics but there have obviously been some rumors that no doubt you guys are cottoning onto as well,” said Red Bull team boss Christian Horner.