The suspected ringleader of the brothel ring is led away by police
Police have carried out a series of raids targeting a suspected prostitution "empire" they believe was worth more than £1m a year.
The alleged ringleader, a 55-year-old woman, was one of six people held following raids at addresses in London, Surrey and Gloucestershire.
Officers also discovered seven women they believe may have been trafficked and forced to work as prostitutes.
They are thought to be from south-east Asia and eastern Europe.
The co-ordinated raids, collectively dubbed Operation Icefall, were led by officers from the Metropolitan Police's clubs and vice unit.
In a statement, the Met said: "The investigation centred on a 55-year-old woman who is believed to have controlled the empire, which netted over £1m a year.
"Together with her partner, she is believed to have used mainly trafficked-women to staff at least four brothels in London and the Home Counties."
These are some of the most vulnerable people that we come across within our operations
Det Ch Supt Richard Martin
The couple were arrested at a property in Leatherhead, in Surrey, where £5,000 in cash, three Mercedes cars and a Vauxhall Transporter van were seized.
Police also raided two other properties belonging to the couple in Gloucestershire, and confiscated two Lamborghini sports cars believed to belong to them.
Two men, aged 46 and 32, suspected of involvement in the alleged conspiracy, were arrested at addresses in Epsom, Surrey and in Berkshire.
Raids were also carried out to shut down four suspected brothels in Surbiton, West Sunbury and Egham, all in Surrey, and West Drayton, London.
There officers say they rescued seven women who they believe were being forced to work as prostitutes to pay off a substantial debt to the brothel owner who had supplied free passage to Britain.
"A constant flow of male visitors" would pay between £60 and £120 for a range of sexual services, police said.
Police seized three Mercedes and two Lamborghinis
Three other arrests were made at suspected brothels in West Sunbury, West Drayton and Egham.
Det Ch Supt Richard Martin, who led Operation Icefall, said trafficked women often suffered "dreadful" experiences.
"Subjected to violence on a daily basis, they have to accept huge debt... which they are then forced to pay off by having sex with numerous clients all day, every day," he said.
"These are some of the most vulnerable people that we come across within our operations and they need and deserve our protection.
"Rescuing these victims and tackling those who organise and profit from this awful trade is our key priority."