Tokyo: Two people have died in a decompression chamber at a Japanese spa, news reports said Monday, with a police investigation focusing on a possible fault with the machine.
A man aged 65 and a 58-year-old woman were found collapsed Sunday in the chamber at a hot spring in Saitama north of Tokyo, Nippon News Network and other media reported.
The door was timed to open automatically after 45 minutes, but the two victims were discovered some 50 minutes after the programme began with the door still shut, the television network said.
They were taken to hospital where they were confirmed dead. The cause of death was not immediately known.
According to its home page, the chamber, named "Pascal Health Cell," is one of a number of pieces of equipment at the spa intended to "help your fitness by improving the inside of your body".
News reports said it reduces air pressure to levels equivalent to those found at a height of 3,500 metres (11,550 feet) above sea level, and helps increase energy consumption.
Police have launched an investigation into the case, with a possible fault in the system the present focus, local media said.
An official from the facility said it would be inappropriate to comment with an official investigation under way.
Bathing and general pampering is a popular pastime in Japan, where naturally-occurring hot springs are a favourite holiday destination.