A DAWN raid on a brothel in Harrow - one of 13 properties invaded by police on Tuesday - resulted in the arrest of a 25-year-old man.
In total, five women and seven men were brought into custody in central London after the Metropolitan Police's Clubs and Vice Unit entered addresses across London and the Home Counties at 7am in order to "smash a criminal gang involved in running a network of brothels".
Five women, who are believed to have been trafficked to Britain and forced into prostitution, were rescued and taken to specialist help centres.
It is not known if any of the seven were discovered at the brothel Harrow, the exact address of which is not being released by the authorities.
The arrests follow the nine-month-long Operation Sanders that sought to expose, according to police, "an organised criminal network concerned with the trafficking of women for the purpose of sexual exploitation".
Detective Chief Superintendent Richard Martin, head of the Met's Clubs and Vice Unit, said: "The experience of the women that are forced into prostitution are absolutely horrendous.
"They experience violence on a daily basis and are subject to huge debt bondage which they are then forced to pay off by having sex with numerous clients daily.
"These are some of the most vulnerable people that we come across within our operations. Rescuing these victims and ensuring their safety is our key priority."
Boris Johnson, the Mayor of London, said: "I'd like to congratulate the Metropolitan Police for such a successful operation - this is exactly the sort of action we want to see to crack down on trafficking and prostitution in London.
"Today, along with Met Commissioner, Sir Paul Stephenson, I launched my strategy to tackle violence against women across the capital. There are too many women whose lives are blighted by violence perpetrated by men, something which is wholly unacceptable.
"We need tougher action to end all violence against woman and I am committed to working with the police and other agencies to achieve this."
Operation Sanders was itself launched in June 2008 following Operation Rize, the investigation into gangs that used safety deposit boxes such as those at Edgware Safe Depository in High Street, Edgware.