The ruling and opposition parties plan to submit two bills to the Diet that will enable police to conduct autopsies without having to obtain the consent of relatives when it is uncertain whether a person died naturally or was the victim of foul play, according to lawmakers.

If enacted, they will be the first laws to articulate the system of identifying the cause of death. Concern about the nation's low autopsy rate has been growing over the years as police-conducted postmortems are few and thus crimes are not investigated or prosecuted. In 2011, autopsies were performed on only 11 percent of bodies handled by police.

The ruling Democratic Party of Japan and the Liberal Democratic Party and New Komeito plan to submit to the current Diet session the bills sponsored by member lawmakers that will oblige police to probe causes of death to ensure criminal acts do not go undetected, lawmakers said Thursday.