The case came to light after the man's wife filed a police complaint against colleagues who threw the man up into the air, accusing them of gross negligence, the Mainichi paper reported on its website.

The man died in September, 10 months after the party attended by around 40 people at an unnamed transport company at an inn in Ritto, near the ancient capital of Kyoto in central Japan.

The fall damaged his neck and backbone, leaving him paralyzed, and he eventually died of blood poisoning, the paper said.