Colin Woodcock, Soca's senior manager for fraud prevention, said: "The perpetrators spend long periods of time grooming their victims, working out their vulnerabilities and when the time is right to ask for money." He said it is crucial that no-one sends money to someone they have only met online.
After they establish a relationship with the victim, the criminal will then ask for financial help.
Although some of those targeted have handed over hundreds of thousands of pounds, the crimes often remain unreported because victims are too ashamed and upset.
In the first major study into online dating scams, researchers at Leicester and Westminster universities found that over 200,000 Britons have been directly affected by online scams, while over a million people personally know the victim of the crime.
We thus believe new methods of reporting the crime are needed." According to the Serious Organised Crime Agency (Soca), romance fraud is organised crime, usually operating from outside the UK.
Their investigations have seen people defrauded of sums ranging from £50 to £240,000.
Criminal groups make initial contact with potential victims online, and then try to move the "relationship" away from the monitored website before carrying out their sting.
Victims are known to suffer emotionally from the loss of a relationship that they believed to be genuine.
Professor Monica Whitty from the University of Leicester said: "Our data suggests that the numbers of British victims of this relatively new crime is much higher than reported incidents would suggest." Researchers questioned 2,000 people through an online You Gov survey.
Action Fraud, the reporting and advice centre run by the National Fraud Authority, identified 592 victims of the scams between 2010-11. Shame and upset However this new study confirms suspicions that the scale of the problem is much bigger, because victims are too ashamed to report the crime.