A 90-year-old triple murderer, reportedly the oldest prisoner on death row, has choked to death on his own vomit at a prison in Fukuoka Prefecture, the government said Monday.

Takeshige Hamada was convicted of killing three people in the prefecture for insurance money over a two-year period from 1978.

According to the government, he was not breathing when found lying on the floor of his cell around 12:50 a.m., and showed signs of vomiting.

He was rushed to a hospital but pronounced dead at around 2 a.m.