A Cornwall, Ont., woman has lost all her money after falling victim to a scam the RCMP are calling the top identity fraud in Canada.

Julia-Shea Baker, a 23-year-old server, lost $4,000 to the "SIN scam," a new version of the Canada Revenue Agency fraudulent act that's been used for years to dupe people out of their money.

It all started two weeks ago when Baker got a terrifying call from Service Canada telling her that her social insurance number had been compromised. The caller identified himself as RCMP investigator Steve Rogers.

You're not being physically held hostage or held for ransom, but it feels that way. It feels like your freedom is on the line. - Julia-Shea Baker

The caller told her a car rented in her name had been discovered abandoned in south Toronto with blood residue on the seats and 10 kilograms of cocaine inside.

The "officer," who gave Baker a badge number and a case number, told her that her name and social insurance number were involved in a drug and money-laundering investigation.

"My heart started racing, my palms started sweating," Baker said. "I was absolutely panicked. I was terrified, absolutely terrified."

When she questioned the officer's story, he called her back from a different phone number. The caller ID showed up as belonging to the Cornwall RCMP. She looked for the number on Google and it seemed legitimate.

In September, the RCMP warned Cornwall residents their phone number was being "spoofed" — used fraudulently to make it look as if scammers were calling from the local detachment.

Call lasted hours

"Steve Rogers" told Baker the RCMP would take care of getting her a new SIN, but to protect her money, she had to transfer her savings to secure gift cards.

He instructed her to drive to grocery stores and pharmacies across Cornwall to buy up Google Play gift cards, all the while staying on the line to make sure she did what she was told.

Under orders from the scammer, Baker spent hours driving to grocery stores and pharmacies to buy gift cards. (Nati Harnik/Associated Press)

After several purchases, her debit card was declined, so the caller told her to go to her bank and withdraw all the cash she had left to buy more gift cards. When she'd done that, he ordered Baker to call the bank to increase her credit limit, then buy yet more gift cards.

"This went on for four and a half hours," Baker said. In that time, she spent $4,000 to buy 35 gift cards.

The whole time, the caller stayed on the line, carefully taking note of the gift card numbers and codes.

Threats, intimidation

Baker said she broke down in tears several times during the ordeal, but the man on the phone kept reiterating she couldn't tell anyone what was going on, and if she did, she could be implicated in the investigation.

He told her that her messages and conversations were being monitored.

"You're not being physically held hostage or held for ransom, but it feels that way. It feels like your freedom is on the line," she said.

Julia-Shea Baker describes how she fell victim to a common scam — and why the story the scammers told her seemed to make sense at the time. 4:40

"Steve Rogers" told her he would call her back at 9 a.m. the following day to arrange to give her a new SIN, but he never called. When she called the original number back, the person who answered didn't speak English.

That's when she went to her local police station and learned she had been scammed. By then, the money was already gone.

"To realize that you've been duped, that somebody has taken advantage of your vulnerability … you feel dirty, you feel violated," she said.

Julia-Shea Baker says she hopes others can learn from her experience. (Supplied)

She said she'd heard of similar scams before, but the "officer" offered her enough information to make her feel the call was legitimate — and urgent.

She's not alone, according to Jeff Thomson, senior RCMP intelligence analyst with the Canadian Anti-Fraud Centre.

He said the SIN scam is the most popular type of identity fraud reported to his unit, and it's on the rise.

From January to July, there were 800 reports of similar scams in Canada. By October, that number had reached 3,000.

Police say it's an adaptation of the CRA scam that became prevalent a few years ago. As people got wise to the fraud, the scammers changed tactics.

Some victims give personal details to the callers, allowing them to steal their identities, while others are tricked into sending money, Thomson said.

Jeff Thomson, a senior RCMP intelligence analyst at the Canadian Anti-Fraud Centre, encourages people to report fraud and identity theft cases to police or the anti-fraud centre. (Jean Delisle/CBC)

Caller ID can't be trusted as a means of filtering out scam calls, he said. The biggest tip-off is if the caller behaves in a threatening manner.

"The government's never going to call you and threaten you into sending money, they're not going to ask for your personal information over the phone in an unsolicited fashion, in an alarming, scary fashion," he said.

His best advice: Just hang up.

Baker said she feels gullible for falling for the scam, and hopes others can learn from her experience.

"If it can help somebody else in the future, then at the end of the day it's more valuable to me than $4,000," she said.