Police today launched dawn raids on suspected people traffickers after receiving intelligence from the Hungarian police.
A total of six people were arrested and ten women, who were believed to be forced into prostitution, were rescued during the operation in Waltham Forest and three other boroughs.
The newly formed Metropolitan Police Trafficking and Kidnap Unit made the arrests on suspicion of trafficking for sexual exploitation, controlling prostitution and money laundering after targeting 15 brothels.
During the investigation, one of the victims escaped from her traffickers and contacted police.
The criminals had been advertising sexual services online, including offering 'unprotected sex'.
The gang is also suspected of operating in Belgium, Austria and Germany.
More than 100 women are believed to have been exploited.
The Trafficking and Kidnap Unit was formed in May 2014.
More than 60 officers are now allocated to investigating trafficking and kidnap.