The iPod nano was always a "hot" item
The Japanese government is investigating a possible battery defect in the iPod Nano music player.
There have been two reports of Nanos overheating in Tokyo, scorching nearby paper.
Economy, Trade and Industry ministry official Hiroyuki Yoshitsune was quoted by the Associated Press as saying the government is in touch with Apple to investigate the defect.
A problem with the lithium-ion battery was suspected, the AP wire agency said.
The report echoes an incident in March, in which the Japanese government stepped in to investigate an iPod Nano that overheated, shooting sparks.
In 2006, Apple was forced to recall some 1.8 million lithium-ion Sony-made laptop batteries that were prone to overheating.