McLaren boss Martin Whitmarsh has pointed the finger at a number of rival teams, including Red Bull, suggesting they are breaking the rules.

His comments, which relate to a system which is believed to alter the ride height, came in the wake of today's qualifying session which saw the Red Bulls lock-out the front row. Earlier, the Austrian cars, even while running on the harder compound, had easily kept pace with those teams running on the grippier soft compound.

"There's evidence there are ride-height control systems which many people thought weren't permissible," he told British F1 broadcaster BBC.

"It looks like Red Bull and some other cars are able to run lower in qualifying than you would expect if they're then going to fill the car with fuel afterwards," he continued. "As you can imagine, we're working quite hard on those systems now.

"The original rulings suggested such systems wouldn't be allowed on cars but we're seeing some cars which seem to have them. We've got to have them fitted as soon as we can, hopefully by China we'll have something on the car.

"Frankly, a few months ago," he continued, "if the engineers had come to me and said: 'We're going to design this system', I would have said: 'Actually, I don't think it's permissible.'"

In terms of aero efficiency, teams need to run their cars as close to the ground as possible. However, under the new, no-refuelling rules, as a car burns up fuel and gets lighter, it should run higher off the ground, thereby compromising its aerodynamic efficiency. McLaren believes that a number of teams, including Red Bull, have come up with a device, most likely involving some kind of ratchet, that changes the ride height as the car gets lighter.

That said, McLaren has enjoyed its own fair share of controversy already this season, including a slot in the rear wing and the so-called F-duct device.