Apple is facing a crisis in Japan after one of its popular iPod Nanos gave off sparks.

Japan's trade ministry has launched a safety investigation, which could lead to major problems for Apple if it leads to a recall. Apple is also looking into the cause and checking whether there have been similar cases.

The incident involved an earlier Nano model sold in Japan, the MA099J/A. The iPod sparked on January 8th in Kanagawa prefecture near Tokyo, the official said. Apple waited to report the incident to the Ministry until March 7th; perhaps it is a little concerned that it flogged 420,000 units a year of that Nano model in Japan.