The A6 L e-tron features a 2.0-litre TFSI petrol engine with 211bhp and a 95bhp electric motor, with a liquid-cooled lithium-ion battery in a protective structure at the rear of the vehicle. Like many other hybrids it can use either power source individually or combine them for maximum performance.

Audi said the car marks part of the next stage in its electromobility programme, following the introduction of Q5, A6 and A8 hybrid models. This would include other models with the e-tron branding, and will cover plug-in hybrids, range extenders, pure-electric and hydrogen fuel cell vehicles.

An electric R8 e-tron will be manufactured in a short production run later this year, while the A3 e-tron will launch in 2014 as a full-scale production model. The A6 L e-tron has yet to be confirmed for production, but the carmaker said it was a technology study of a possible future vehicle that could be produced alongside the A6 in China.