Tokyo, (AFP) - A drunken Japanese policeman who fell asleep on duty has lost investigation documents containing the personal information of more than 400 people, including a suspected crime suspect, police and local media reported.

A police official told AFP on Monday that the 49-year-old policeman lost the bag containing the documents in the western Hyogo region between 11 p.m. Friday and 5 a.m. Saturday.

He pointed out that the documents include names and addresses, without giving further details.

Prominent Japanese media, quoting police officials, reported that the policeman went out to drink alcohol with his colleagues, then fell asleep while returning home with the bag in his possession.

When he woke up, he found himself near a train station and could not find the bag, according to media reports.

This is not the first time that similar incidents have occurred in Japan.

In June, Amagasaki city authorities reported that a contractor lost a bag containing a USB memory stick containing personal data for the area's 460,000 residents after he went out for a drink and fell asleep on the road on his way home.

The bag was found the day after the news broke.