A new sophisticated phone-based scam targeting Canadians has drained five victims of more than $5.1 million, Toronto police said Friday.

The scammers pose as retailers, claiming to alert the victim of fraud in progress on their credit card and asking them to call 911 or their bank. Though the victims think they’ve hung up and dialed another number — some insist they heard dial tones — the fraudsters appear to be using technology that allows them to stay on the line with the victim.

Then, posing as a 911 operator or a bank employee, the original caller convinces victims to move their money, usually via wire transfer, into an external bank account while the fake credit card fraud is investigated.

“They’re pretty good pitch men,” said Det.-Sgt. Ian Nichol. “There is a foreign component to this investigation but I’m not in a position to say where the calls are coming from…There may be a domestic component as well and that’s all I can say.”

Nichol said the scheme appears to be targeted at land lines, rather than cellphones.

“I suppose that there’s something specific with the technology employed in land lines that may make this possible,” he added.

The victims weren’t those who would typically be vulnerable to such a scam, Nichol said.

“They’re all on the ball,” he said. He declined to comment on their financial status.

Nichol said he believes the “emerging” scheme is targeting people across Canada, and has existed for at least four months. Some of the victims said it appeared the scammers already had some of their banking information.

“That doesn’t mean they actually had it,” he said. “It could mean the victims were duped into providing it.”