Fukui -- An academic at a top Fukuoka university died in hospital after he was transferred from the Fukui headquarters of the all-white Panawave cult, police said.
The man, Satoshi Chigusa, an assistant professor at Fukuoka University of Education, was a regular visitor to the facility and had been on summer vacation since Aug. 1.
Doctors found numerous bruises on the 40-year-old man's back when he was transferred to a Fukui hospital after he collapsed in the facility on Thursday. He died later in the day.
Coroners announced Friday that they were unable to determine the cause of his death, although the most likely reason for his demise was the combination of heatstroke and shock related to his external injuries. The temperature in Fukui hit 35.2 degree Celsius on Thursday.
Police are questioning Panawave members in a bid to establish why Chigusa's back was covered with bruises and the events leading up to his collapse.
Cult sources acknowledged to the Mainichi that it is common practice to hit members with cardboard when he or she falls asleep or loses concentration.
Panawave and its guru Yuko Chino attracted considerable media attention earlier this year as the cult's all-white motorcade wandered around central Japan in preparation for their predicted doomsday, which never arrived.
The cult is known for covering virtually everything in white cloths wherever they go to protect their leader and themselves from electromagnetic waves.