Tokyo police admitted they handed over the wrong body for burial after family members mistakenly made a positive identification.

The bizarre situation was discovered only after the remains were cremated and the man thought to have died turned up at a relative's house in May.

Disclosing the case June 12, the criminal affairs division of the Metropolitan Police Department explained that a man was hauled unconscious from the Edogawa river in the capital's Katsushika Ward in late June of last year. A hospital confirmed the man's death.

The local Kameari Police Station suspected that the body was that of a man in his 40s from Matsudo, Chiba Prefecture, who had been reported missing by his family three days earlier. It asked the family members to identify the body.

Armed with a positive ID, police handed over the body for cremation.

For months afterward, no one thought more about it. Then in May, the man who everybody had assumed was dead visited the home of relatives, who in turn, reported the matter to police on June 6.

Police went through their files and found a set of fingerprints, which after an analysis, proved to have been taken from a different man in his 30s who lived in Tokyo.

In cases where relatives make a positive identification after viewing the body, fingerprint and DNA verification is not required, police said.

Tokyo police contacted family members of the man in question to start procedures to pass the cremated remains to them.