A rare defect in the first-generation iPod Nano is causing a consumer scare in Japan.

The Japanese Ministry of Economy, Trade and Industry has warned that the media player has been responsible for at least three fires. No major injuries were reported in any of the incidents.

The problem lies within the battery unit. Certain units can be prone to overheating which can then lead to a fire. The issue is not believed to affect any other iPod models or later generations of the Nano.

Apple is trying to ease the fears of customers that their iPods may be the next to combust.

The company claimed in a statement to The Wall Street Journal that the defect has been traced back to a single supplier and is present in only .001 per cent of the first-generation Nano models.

"Apple has determined that, in very rare cases, batteries in first-generation iPod Nanos sold between September 2005 and December 2006 can overheat causing failure and deformation of the iPod Nano," the company said.

"There have been no reports of serious injuries or property damage, and no reports of incidents for any other iPod Nano model."

This is not the first time that Apple has had to deal with exploding batteries. In 2006 the company was among the long list of major vendors forced to recall Sony-made batteries due to a similar fire risk.