The U.S. Department of Justice has made 565 arrests internationally in an operation to crackdown on fraudulent mass-marketing schemes that bilked $1 billion from 2.8 million victims.

The sting, called Operation Global Con, took place over the past 15 months and sent both U.S. and foreign law enforcement officials searching for con artists in the U.S., Canada, Spain, Netherlands and Costa Rica.

There were nine sweepstakes-related arrests in Costa Rica, where individuals fraudulently offered sweepstakes winnings to U.S. residents. Many of the individuals represented themselves as employees of the U.S. Department of Commerce or used the department's logo in documents sent to unsuspecting consumers.

In the schemes, telephone callers promised substantial amount of money as major sweepstakes prizes. But to get the prize, consumers were asked to pay bogus fees or taxes on the winnings, but never received any winnings. In some instances, the con artists claimed to be with nonexistent companies or government agencies to gain credibility with prospective victims. Spain had the most arrests (310), followed by the U.S. (139).

"These criminals used telemarketing, the Internet, and mass mailings, to cheat unsuspecting people through bogus investments, fake lotteries and sweepstakes schemes, phony credit cards, and tax frauds," said U.S. Attorney General Alberto R. Goncalves in a statement.

For more stories on legal issues