CON-men who pressure people into buying worthless shares have started targeting victims in North Yorkshire.

At least four cases have emerged across the county - and although police are not giving details they say a "considerable" amount of money has been lost to what are known as Boiler Room frauds.

A Boiler Room is a bogus stockbroker, usually based overseas, who cold-calls investors and pressures them into buying worthless shares.

Historically, victims have usually been middle-aged men with previous experience of share dealings, who typically lost £20,000 each to the fraudsters.

However, Operation Archway, which is the national response to the problem co-ordinated by the City of London Police, has seen a sharp rise in the number of women and younger men being targeted.

And in the current economic climate, the fraudsters are also starting to target victims who have redundancy money or those who are not experienced investors.

The head of North Yorkshire’s financial investigations unit, Detective Inspector Ian Wills, said: "Boiler Rooms have developed new strategies to target victims such as a promise to recover monies lost to the original Boiler Room, in the format of a ‘Recovery Room’.

"In addition, victims are being encouraged to sell previously highly-regarded blue-chip company shares, such as banks and financial institutions, and to invest in green and new technology shares marketed by the Boiler Rooms."

Det Insp Wills said the fraudsters were usually well spoken, knowledgeable - and extremely persistent.

He said: "They might call their victim several times with offers of research, discounts on stocks in small overseas companies, or shares in a firm that is about to float.

"To discourage investigation by law enforcement agencies, the deception is typically perpetrated using different legal jurisdictions for the various parts of the overall offence."

He said the police advice was not to accept cold calls, however persistent - and always seek legal and independent financial advice.

For further information and advice on Boiler Room frauds visit the website www.cityoflondon.police.uk/CityPolice/ECD/Fraud/boilerroom.htm