The FIA have reportedly declared Red Bull's Renault engine legal after questions were raised by rivals Mercedes.
Following Red Bull's queries about Mercedes' rear wing, the tables were turned in Sepang when the latter asked for clarification about the reigning World Champ's engines.
As of this season teams are only permitted to cut up four cylinders off-throttle through the corners, however, Mercedes - based on audio analysis - believed Red Bull could be cutting more.
The team raised their concerns with the FIA, who reportedly declared that there is nothing illegal about Red Bull's engine mapping.
This is a sentiment echoed by McLaren team boss Martin Whitmarsh who explained the situation, telling grandprix.com: "Mercedes has presented us with some audio analysis. It's quite complex but the upshot is, they say it shows that Red Bull are cutting more than four cylinders, which you are not allowed to do.
"Actually, the cut pattern is not determined, so you can cut as many cylinders in whatever order you like. We've got the data and we can see quite clearly that there are four cylinders being injected, four cylinders firing and they are timed at the right time, so there's every reason to suppose that there's combustion going on.
"Moreover, the throttle opening at that point is not any more than it is normally, so if they are doing anything funny they are not opening the throttle any more, so it negates the arguments a lot.
"As far as we are concerned it's entirely legal because they are not cutting more than four cylinders, which is what the contention is."