Of the 1,592 deaths in Japanese prisons and detention houses in the 10 years to 2002, only 68 required autopsies because of questions over the circumstances of death, according to a Justice Ministry official.

The number of postmortem examinations prior to an autopsy being carried out was 484 during the same period, Kenji Nakai, head of the Justice Ministry's Correction Bureau, told the House of Representatives committee on judicial affairs Tuesday.

The 68 autopsies, included in the total number of postmortem examinations, were conducted to pinpoint the cause of death, Nakai added.