Lawyers have been put on an international money laundering alert by a new police fraud unit, established by the City of London police.
The Financial Investigation Unit (FIU) warned the profession that they may unwittingly be representing clients with connections to organised crime.
Detective Chief Inspector Tony Thomas, head of the FIU, said: "Where transactions are unusual or give rise to suspicion, lawyers should conduct due diligence above and beyond what would normally be required." He added: "Do not be put off by the possibility of a loss of commission."
City police believe the FIU is the first organisation to concentrate on substantial and sophisticated money laundering.
The unit will form part of the capital's Fraud Investigation Department.
Thomas said: "The Law Society is aware of the danger of handling other people's money or using shell companies for the purposes of deception."
He emphasised the increasingly complex and international nature of money laun dering and the need to protect the City's reputation as a world financial centre.
The aims of the FIU, which may co-opt lawyers for particular cases, include identifying methods used by criminals to evade reporting systems.
Another objective is to investigate the chain of transactions to discover both the initiating offence, the principal offenders and those involved in the laundering process.
Thomas said money laun dering, by its nature, is about the ways criminals find to dispose of their ill-gotten gains around the world, adding that methods typically involve the international financial markets, commodities, art and antiques. He said organised crime syndicates are also involved.
Diane Burleigh, head of court business at the Law Society said: "Solicitors know about the danger posed by money laundering to their businesses. Where there is uncertainty, our advice is to contact us immediately."