Two men have died after collapsing in a sauna near Waterloo station in south London.
A 39-year-old man was found dead just after 8am on Saturday, while a 46-year-old man died later in hospital. A third man, aged 34 who also collapsed, was released from hospital on Monday.
The incident took place at the Pleasuredrome sauna on Cornwall Road. Police are appealing for a fourth man seen entering the venue with the 39-year-old as soon as possible. He is described as a slim, white man, aged 25 to 35, with brown hair and a goatee beard and approximately 6ft tall. Officers are concerned for his welfare.
A post-mortem examination on the 39-year-old took place on Monday at Greenwich mortuary, but failed to establish a cause of death. Lambeth Police said it was waiting for further toxicology tests.
A post-mortem on the 46-year-old will take place on Thursday at Greenwich mortuary. Both deaths are being treated as unexplained.