Red Bull team boss Christian Horner late on Saturday denied that the RB6 car is running a controversial ride-height adjustment system.
After Sebastian Vettel and Mark Webber dominated qualifying in Melbourne, McLaren chief Martin Whitmarsh suggested they had been boosted by a system that allowed the cars to remain low to the ground despite the huge load of fuel that must now be added for Sunday's race.
Whitmarsh said he had "evidence of ride-height control systems" being in use, "which many people wouldn't have thought were permissible", and that McLaren would therefore have to also design one.
But Red Bull's Horner told the BBC that he could "absolutely guarantee" the RB6 has no such system.
It must be noted that Whitmarsh had said after qualifying that he thought "some cars" - not just the Red Bull - were running a ride-height system.
Before leaving Albert Park late on Saturday, Mercedes' Ross Brawn indicated that he is aware of the claims about the systems, and encouraged the FIA to make a ruling.
Horner, meanwhile, hinted that sour grapes might be in play, after he was the one who blew the whistle on McLaren's F-duct prior to Bahrain.
"There are funny things happening at McLaren -- Lewis managing Mark, Ron reckoning we have a fuel problem and now Martin reckons we have a ride-height control," said the Briton.