Nissan has warned US drivers to keep mobile phones away from electronic car keys because the key's codes can be erased. 

The car manufacturer has asked owners of its Nissan Altima and Infiniti G35 sedans to leave at least an inch between the keys and a mobile phone. 

Nissan's I-Keys use wireless technology to operate the car doors and start the engine. If the code is wiped drivers would be unable to open or close the doors or travel anywhere in the vehicle.

"If the I-Key touches a cellphone, outgoing or incoming calls have the potential to alter the electronic code inside the key," Nissan spokesman Kyle Bazemore told Reuters. "The car will not start and the I-Key cannot be reprogrammed."

Bazemore explained that the problem had been found only in a "very small percentage" of the models sold, and that dealers had been issued with new keys in case owners encountered the problem.

Nissan said that it will launch a new version of the I-Key later this year.