Red Bull are under investigation by the stewards for a breach of the technical regulations ahead of today's German Grand Prix.

Technical delegate Jo Bauer has questioned the engine torque map of the cars of reigning world champion Sebastian Vettel and team-mate Mark Webber.

The suggestion is the engine's throttle is more open than it should be for a given accelerator position. The effect is more air through the engine, and in turn over the exhaust to aid aerodynamics and downforce.

Whilst teams can use exhaust gases to blow over certain areas of the rear bodywork, they cannot alter the torque maps for greater engine performance which would in turn produce more gases.

It has been suggested the overall effect is minimal, but it is illegal, leaving the stewards with a race against time to resolve the issue ahead of the 2pm local time (1pm UK) start of the race.

A technical report issued by Bauer reads: "Having examined the engine base torque map of car numbers 01 (Vettel) and 02 (Webber) it became apparent the maximum torque output of both engines is significantly less in the mid-rpm range than previously seen for these engines at other events.

"In my opinion this is therefore in breach of Article 5.5.3 of the 2012 F1 Technical Regulations as the engines are able to deliver more torque at a given engine speed in the mid-rpm range.

"Furthermore this new torque map will artificially alter the aerodynamic characteristics of both cars which is also in contravention of TD (technical directive) 036-11."

One potential penalty for Red Bull, if found guilty, would be both Vettel and Webber start the race from the pit lane as their times for qualifying would be excluded.