Dating websites experience a surge of sweethearts signing up around Valentine's Day and that could mean a scourge of scammers.

"Valentine's Day is like Christmas for scammers," said Suzanne Edmundson, a private investigator who owns Vancouver-based Axiom Investigations Ltd.

"It's at that time that people want to be in a relationship. They want to meet someone and unfortunately, that's when people are most vulnerable and that's when these scammers do the most damage."

She said she's investigated at least one romance scam per month in her 11 years in the business.

Suzanne Edmundson

Suzanne Edmundson is a private investigator in Vancouver, B.C. (Supplied by Suzanne Edmundson)

"There are all types of romance scams, both online and in person," she said. "Often times the in-person scam is far more devastating than the online. These people truly believe they are in a mutually loving relationship."

According the U.S.-based dating website OKCupid, sign-ups increase at least 15 per cent heading into Valentine's Day, one of their biggest weeks of the year.

Daniel Williams, senior fraud specialist with the Canadian Anti-Fraud Centre, said scammers are increasingly playing the long game.

"We've had many, many cases where the scammers wait eight, nine, 10, 11 months before asking for any money," he said. "They can really play it out, nice and slow, develop the relationship, and then by the time the money is asked for, the victim is thinking, 'This is my true love.'"

"By the time the need for money comes up, you've fallen in love." 

He said the financial cost of romance scams is massive and the per person cost in Canada is usually much higher than in other mass-marketing fraud cases.

Daniel Williams

Daniel Williams is a senior fraud specialist with the Canadian Anti-fraud Centre. (CBC)

"For 2015, we are looking at $16.9 million," he said, "672 victims of out of a total of 16,767 victims of all mass marketing fraud. So they are low numbers of victims. That's comparatively small, but the amount of money they are losing is huge.

"We know from a lot of experience that what we see on our database, what is reported to us, is between one to five per cent of what is out there," he said. "The scammers are so very good at what they do." 

Ontario man taken in

An Ontario man, whom CBC News is not identifying because his case is currently being investigated, said a woman from the Philippines he met online on Valentine's Day scammed him out of thousands of dollars over the course of their relationship.

According to his complaint to police, he struck up an online relationship with the woman on Valentine's Day three years ago through a social media site.

The man said he met her in person in Canada five months later. After dating for about 10 months, he asked her to marry him, he said. 

He said a month later, she asked for $1,700 for a plane ticket to the Philippines because her mother was sick. He agreed to give her the money, which she demanded in cash. Two months later, she asked for $200 per month for her mother, which he said he reluctantly paid. He also paid another $1,700 for plane tickets and winter boots. In early 2015, he said, she also asked for $500 per month for daycare fees for her daughter in the Philippines and $10,000 for breast implants, which he refused.

Right before they broke up last January, the man said, she demanded that he pay her $200 for every time they had sex and provide her with a personal allowance. At that point, he said, he stopped seeing her and asked her to return the engagement ring he bought her, which she did.

"On a personal level, it's devastating," he said. "It will take me years to recover."

The man said he posted his story on a number of social media forums to warn others about romance scams.

"Police and the courts are pretty useless with dealing with these, which means victims generally are left to fend for themselves," he said. "It's obviously a fraud to all of us; police say that it is a civil matter."

He took the woman to small claims court in Ontario where he recovered some of his money, about $3,000.

Edmundson said in-person scams can also can be even trickier to uncover than online scams.

"To not only get taken financially, now you also have your heart broken," she said. "People don't want to believe that the person they love is betraying them."

Manitoba RCMP came out with a list of their own suggestions to help keep lovers safe this Valentine's Day: