A possible battery fault which caused iPod Nanos to overheat dangerously is being investigated in Japan.
The government ordered an inquiry after reports that two iPod Nanos overheated in Tokyo, scorching nearby paper and woven straw mats.
The report disclosed by the Ministry of Economy, Trade and Industry follows a similar report in March about sparks shooting out of a Nano.
A government spokesman told the AP news agency they have been working with iPod maker Apple to investigate the cause, and a defect in the lithium-ion battery is suspected in all three.
The iPods began to overheat while they were being recharged, said the spokesman.
He would not say who made the batteries, and said it was unclear whether the same battery was used around the world.
The spokesman said the two latest cases involved an iPod Nano, model number MA099, which singed nearby paper in August, and model MA005, which burned a Japanese traditional ‘tatami’ mat, in January.
Both players were twisted out of shape from the heat and became unusable, he said.
The government has instructed Apple Japan to find out the cause of the problems and report back to the government.
Lithium-ion batteries have been blamed for a series of blazes in laptops that have resulted in massive global recalls.
Which? contacted Apple over the Nano issue yesterday, but it was waiting for further information before commenting.
In December 2006, Which? reported on a case in the UK where a 13-year-old girl recharged her iPod Shuffle through her home computer and the device overheated and started to melt.
Apple agreed to replace her iPod, which was manufactured in April 2005, with a newer version.