A gay sauna on Albert Embankment has been closed after three men were taken ill early on Sunday morning.
Police were called to Chariots Sauna at Vauxhall Cross by the London Ambulance Service at 0.40am on Sunday following reports of drug-related activity.
"Officers attended and spoke to a man in his thirties who admitted consuming class A drugs," said the Metropolitan Police in a statement.
"He was taken to a north London hospital where he remains in a stable condition.
"Two other men were subsequently found collapsed inside the club.
"Both men were conveyed by London Ambulance Service to a central London hospital where they remain in a stable condition."
No-one has been arrested and police officers based at Brixton are investigating.
According to police, the sauna has been closed as a result of this incident.