Perpetrators target dating websites or social media, regularly posing as soldiers or models to build intimate relationships with victims and ultimately exploit them for cash, researchers at the U.K.'s Leicester and Westminster universities said.
Their findings, based on a survey of more than 2,000 people by online polling site YouGov, support a prevailing theory that people fleeced by online romances do not go to police due to feelings of shame and heartbreak.
Action Fraud, the reporting and advice arm for the U.K.'s National Fraud Authority, received 592 accounts of online dating scams from 2010 to 2011. They accounted for a total of £8.5 million in losses, A ction Fraud's quality assurance officer Steve Proffitt told msnbc.com.
But according to University of Leicester psychology professor Monica Whitty, one of the study's lead researchers, that number represents a small fraction of the crime's financial and emotional impact.
Using a formula that took into account all Internet users in Britain over the age of 18 and the total population, Whitty's team concluded that more than 200,000 people were victims of online dating scams.
"The thing that's very unique about this scam is that there are 'double hits,'" Whitty told msnbc.com. "It's not just the money — it's also the loss of a very important relationship that they find devastating and very hard to get over."
Researchers found the crime affects all groups over 18 years of age and impacts men and women equally, dispelling a widespread assumption that single women over the age of forty are disproportionately impacted.
A telling statistic reflects the scam's power: In the past year, one third of victims lost £5,000 ($7,850) or more. One individual lost £240,000 ($377,000).
"It sounds silly on the surface, but when you trust someone, they know everything about you, there's a crisis that hits, and you don't have much time to decide, why wouldn't you do it?" Whitty said.
The racket's growing complexity has made it increasingly effective.
"Often it is highly organized and sophisticated gangs making up characters, and painstakingly capturing the information people provide," a spokesperson for the U.K.'s Serious Organized Crime Agency (SOCA) said.
According to SOCA, the frauds generally originate outside the U.K. in West African countries like Nigeria and Ghana, and can involve several false identities. Relationships are cultivated over months or even years on dating sites, Internet forums or through email, inevitably leading to requests for cash via Western Union or a similar agency.
The false appeals typically specify a need for travel money, payments for sick relatives or fees to reclaim confiscated possessions, SOCA's investigations have found.
The international nature of online fraud poses numerous difficulties for law enforcement, so authorities policing such scams say public awareness is crucial. The researchers found 52 percent of those surveyed had heard of online dating scams and one in 50 British adults using the Internet knew a victim personally.
"The one thing that I would put forward is don't send money to someone you don't know," Action Fraud's Proffitt told msnbc.com.
If you are caught in a scam, however, "the only way we're going to combat this is through the intelligence [victims] provide," he said.