Japanese authorities have found the body of a man in the landing-gear bay of a commercial airliner arriving in Tokyo from New York.

A mechanic at Tokyo's Narita Airport found the man's body in one of the wheel bays of the Delta Boeing 777.

The man was dressed in blue jeans and a long-sleeved shirt and was not carrying a passport or any personal belongings.

It is unclear if the man was a stowaway or if his death was an accident, but doctors say he probably froze to death or suffered a lack of oxygen from altitudes of more than 10,000 metres.

Japanese authorities have appealed to US police to help identify the man.