Apple iPod fire probe after Nano shoots sparks while recharging

An investigation into the safety of the iPod Nano has been ordered after a reported case of one of the popular music players shooting out sparks while recharging.

A Japanese official investigating the possible defect in the Nano said a problem in the lithium-ion battery is suspected in model number MA099J/A.

The problem, which surfaced in Kanagawa Prefecture south-west of Tokyo in January, was reported by Apple in March.

No-one was injured in the small blast but lithium-ion batteries have been blamed for a series of blazes in laptops recently that have resulted in massive global recalls.

The Japanese government has instructed Apple to find out the cause of what it is categorising as a fire linked to the iPod, and ordered the company to report back.

About 425,000 iPods of the same suspected model were shipped into Japan by Apple.

It was unclear how many have been sold and how many might still be in stores.

The iPod has been the symbol in recent years of the successful fashionable image of Apple.

But its sales momentum may be gradually running out of steam.

Apple sold just 22.1million iPods during the holiday quarter ending December 31 - fewer than the 25million units that analysts expected it to sell.

This has raised fears that the company may suffer as it tries to convince consumers to buy higher-end iPods - a key part of its strategy.

The batteries in Apple products have had some problems in the past, mostly connected to them wearing out - not being prone to fires.

In 2006, Sony apologised to consumers for defective lithium-ion batteries found in Sony laptops and products by Dell, Apple, Lenovo and other major manufacturers.

The Tokyo-based company recalled about 10million batteries following reports that some Sony power packs had caused computers to overheat and burst into flames.

The lithium-ion battery is considered an overall good technology due to its size, charge efficiency and ability to be shaped to fit the product.

However, its suspected tendency to catch fire is a major reason Toyota and other car makers are being cautious about using it in ecological cars.

Toyota's Prius gas-electric hybrid uses a different kind of battery, and the switch in future green models to the lithium-ion battery will be seen as a considerable breakthrough.

Shipments of the iPod model began in September 2005 and were discontinued after September 2006.