Christian Horner has confirmed that Red Bull's engine supplier Renault is now working with Mario Illien.
As the French engine marque faltered at the start of the new 'power unit' era, rumours Renault had turned to Swiss Illien - one of the most famous engine specialists in all of motor sport - and his company Ilmor began to swirl.
Illien was then spotted in the Red Bull garage in Abu Dhabi.
"It is great that Renault are now working with Ilmor," Horner, boss of Renault's works team Red Bull, is quoted by the French magazine Auto Hebdo.
"The company has been faced with similar problems in Indycar. Mario comes with a lot of experience and is able to look at the problems with fresh eyes and perspective."
Modelling, simulation and optimisation
Horner also said Red Bull is playing an active role in helping Renault to chase down dominant Mercedes.
"I'm talking about modelling, simulation, optimisation of air flow, things like that - areas where we have some experience and we can help," he revealed.
Mercedes' rivals are having to simply up their game in the battle against F1's new power, given that efforts to change the engine rules for 2015 failed.
Another way out
Lotus, on the other hand, is going from Renault to Mercedes for the 2015 season, with a team engineer revealing the extent of the problem to Auto Motor und Sport by revealing the switch "gives us 85 horse power more and 18 kilograms less".
It's an insight into the dilemma facing Mercedes' rivals, who may be helped by Bernie Ecclestone at Thursday's meeting of the Strategy Group.
The F1 supremo is trying to scrap altogether the turbo V6 rules for 2016.
"I believe if you got everybody in the room, secret ballot, there would only be one company interested in retaining this engine, and that is Mercedes," he said.