GUANGDONG investigators plan to question the Hong Kong boss of a sauna where 18 workers burned to death. The move comes after revelations yesterday that the Guangtaoge Sauna operated for seven years without meeting the Government's fire safety standards. Investigators said they would seek the assistance of Hong Kong proprietor, Lau Wing-choi, but his whereabouts are unknown. Officials plan to question both Mr Lau and local inspectors in Guangdong. The structural design of the sauna had never received official approval, according to yesterday's Guangzhou Daily. 'The sauna parlour has had no official approval from the fire department since it started construction and has continued to operate without the standard anti-fire devices for seven years,' it said. The six-storey building housing the sauna had few windows and the main entrance served as the only fire exit. Flammable materials such as timber were used to separate rooms. No fire extinguishers, hydrants or automatic sprinklers were installed, contrary to China's safety regulations. Fire department vice-director, Guo Baolun said yesterday: 'I've never heard that a sauna can operate without passing our tests. 'We are going to launch a probe and then establish whether our officials and the owner should be charged, and what responsibilities they should bear.' There are more than 300 entertainment premises and shopping centres in Guangzhou but many have yet to meet official fire safety requirements. Eighteen female workers died in the fire on Friday night. Their bodies were sent to the Guangzhou No 1 People's Hospital. The hospital yesterday declined to identify the victims. 'All of the women were certified dead before arriving at the hospital and all the bodies were to be sent to funeral parlour,' it said. It was the most serious fire since 1976, when 26 people died in Guangzhou city.