The Financial Services Authority (FSA) and City of London Police have uncovered a 'master list' of 10,000 UK names circulating among boiler room share fraudsters.
The watchdog says it has written to 6500 homes across the UK to warn people that they may be a target for fraudsters and directing them to a secure consumer helpline which they can call for more information.
Boiler room fraudsters usually contact people by telephone and use high pressure sales tactics to con investors into buying non-tradable, overpriced or even non-existent shares. Boiler rooms are unauthorised, overseas-based companies with bogus UK addresses and phone lines routed abroad.
Detective shief superintendent Steve Head, head of the City of London Police's Economic Crime Directorate, says: "Intelligence suggests that this list of people from across the UK is currently being shared amongst boiler rooms. I would urge those people who receive a letter from us in the next few days to contact the FSA and City of London Police on the 'Operation Warn' helpline. All the information the public gives us as a result of Operation Warnwill help in the fight against boiler room fraudsters."