Tesla, the US electric carmaker, and BMW are discussing a possible battery and lightweight materials alliance, according to German media reports.

Elon Musk, CEO of Tesla, told the German news magazine Der Spiegel that the two companies "are talking about whether we can collaborate in battery technology or charging stations" adding that he expects Tesla to have its own battery production plant in Germany within six years.

Musk also said that BMW's use of carbon fibre reinforced body parts on its i3 and i8 models and produced in conjunction with supplier SGL was "interesting and relatively cost efficient".

BMW and Tesla met in June to discuss creating charging stations for different types of electric vehicles.