Engine guru Mario Illien has denied that he is helping Red Bull Racing develop an engine for 2016 that will be based on Renault's latest upgrade.
According to Judge13, Illien has spent the past year working inside Red Bull's headquarters in building 9 where he has assisted Renault in "solving fundamental design flaws in their F1 power unit."
The report added that the engine that the Swiss engineer has been working on will be used next weekend in Brazil after Renault and Red Bull agreed joint intellectual property.
Illien, however, had denied having any role in Renault's upgrade.
He told Auto Motor und Sport: "I know nothing of a dispute. I also have no idea what upgrades Renault has incorporated in its modified engine. I cannot imagine that a large company like Renault [would] secretly install my development."
He did confirm, though, that he had done some work with the four-time World Champions and their engine partners at the beginning of 2015.
As for the claims that Illien would now help Red Bull develop an engine of their own based on the latest Renault upgrade for 2016, the former Ilmor boss says he is more keen on helping create an independent engine.
Last month a proposal for a cheaper client engine was put on the table with 2017 being the year it could come into being.
Illien added: "I will look then at what the tender says and decide what I'm doing."