Four people are being held after a raid on a suspected brothel in east London.
A 50-year-old Thai man and a Thai woman, aged 43, were arrested at The Sauna in The Grove, Stratford, on suspicion of helping to run a brothel.
Two Polish men arrested at an address in Forest Gate, east London, are suspected of controlling prostitution.
Seven women of various nationalities, including Brazilian, Lithuanian and Thai, who were working at the sauna, have been interviewed by police.
Officers from the Metropolitan Police's clubs and vice unit carried out the operation on Wednesday night as part of Pentameter II.