Officers of the newly formed National Criminal Intelligence Service have approached organisations including the Association of Estate Agents, the Yacht Charter and British Marine Industries, as well representatives of the travel and motor trade.
At first the squad concentrated on large financial institutions but the success of co-operation between investigators and bankers saw a big increase in the amount of information disclosed by the banks.
'We became aware that not all money launderers put their cash into bank accounts. Money was going into property, cars, yachts, luxury holidays and other assets,' said Peter Solkhan, of the the service's financial unit.
'Criminals are becoming much more aware that we receive information from the banks and the building societies,' he said.
One south London drug dealer is known to have laundered hundreds of thousands of pounds through international house purchases.
Det Chief Insp Charles Hill said: 'It is an offence if someone knowingly fails to disclose drug laundering activities or tips off someone their transactions are under investigation.'