Japan's trade and economy ministry is now officially investigating the explosive nature of the iPod nano, Engadget reports.

The unit in question is model MA099J/A. That's the first generation iPod nano, the old black and white plastic little number that's already reported to "spew chest high flames, cause bedroom fires, and explode across the floor."

The latest incident occurred in January, when a 1st-gen iPod nano reportedly "shot out sparks while recharging." The current word is that the Japanese ministry strongly warned Apple for failing to report the incident when it occurred, as required by law, the report said. Apple's filing with the ministry came on March 7th, about two months later.

Photo credit: Engadget