A man has been arrested after police raided exchange bureaus they suspect of laundering £3m of criminal profits.
A 27-year-old from Sutton was arrested on Constance Road and was among the six held around London when officers from the MPS, HM Revenue and Customs (HMRC) and the Serious Organised Crime Agency (SOCA) made the raids.
Officers hit ten money service businesses, through which profits from crime are believed to have been laundered.
The addresses are located in Westminster, Sutton, Waltham Forest, Kensington and Chelsea, Hammersmith and Fulham, Barnet, Hounslow, Brent and Camden.
Detectives suspended licences and also seized £180,000 found on the premises and believed to be derived from criminality.
Detective Superintendent Nick Downing, of the MPS Specialist, Organised and Economic Crime Command, said: "Today's operation is part of an ongoing and intelligence-led investigation during which our officers have already seized £3.7 million believed to have been laundered at MSBs between April 2012 and May 2013.
"Of this money, £850,000 has already been confiscated by the courts."