CALGARY (CBC) - An investigation into a scam that saw about $3 million in fees and taxes collected from Americans who thought they had won a lottery has led to charges against several Calgary residents.

RCMP announced the charges Wednesday in what they are calling a cross-border telemarketing scam.

Two Calgary residents have been arrested and Canada-wide arrest warrants have been issued for five more people from the city. Police also arrested a Burnaby, B.C. resident and a Toronto resident.

A total of 261 charges have been laid, including money laundering, fraud over $5,000, and conspiracy to commit fraud.

The victims were contacted by letter or phone and told they had won a lottery or sweepstakes, but were required to pay taxes, administration fees or lawyer's fees before they could collect their winnings, which didn't exist.

Insp. Frank Smart said there were more than a dozen victims, but police aren't aware of any in Canada.

"If sounds to good to be true it probably is. When someone is offering you a prize, or something like a lottery or sweepstakes, in return for you giving them a phone call, personal information, or money up front, you should always be wary of that."

The victims' losses ranged from thousands to tens of thousands of dollars, with more than $3 million collected in total.

RCMP said they worked with several agencies, including U.S. postal inspectors and border agents, during their investigation.