A woman in her 30s from Greenhithe is one of seven suspects arrested in a major organised crime bust.
She was detained at her home in Alexander Road at 6.30am this morning at the same time six other residential premises across Kent, London, Surrey and east Sussex were raided by detectives as part of Operation Octopod.
Police say the group is linked to one of the longest established and most high profile organised crime gangs in the country.
The suspects, including a trained accountant-turned property developer and a solicitor, are believed to have laundered large sums of money through an investment scheme.
Detective Chief Superintendent Tom Manson of the Met’s Specialist, Organised and Economic Crime Command, said: "This is continuing activity, bringing together some of the Met's most skilful teams to target a highly harmful organised crime group which we believe also has links across Britain and Europe.
"The group as a whole is known to be involved in serious and violent crime which is harming people and damaging communities across London.
“We believe those arrested today are laundering huge quantities of cash.
“We believe that they - with other members of the group - are responsible for a multi-million pound criminal business, the proceeds of which are laundered and either pumped into other illegal money-making schemes or spent on luxurious living.”
Around 50 police officers and specialist financial investigators from the London Regional Asset Recovery Team, the Territorial Support Group, the dog unit, local police teams and Revenue and Customs executed warrants this morning.
Officers seized approximately £100,000 cash at an address in Shoreditch and a Proceeds of Crime Act production order was served on an accountant's office.
Detectives are continuing to search all the premises raided while financial documents, computers and mobile phones have already been seized and will be sent away for forensic examination.
As part of Octopod, 15 people were arrested by detectives in February after evidence of conspiracy to assault, money laundering, fraud and revenue offences was gathered.