Two dozen people cheated casinos in several U.S. states and Canada out of at least $3.3 million over five years by using technology and bribes to rig card games, federal prosecutors alleged in unsealed indictments.

Members of the organization would signal a dealer to do a false shuffle and bet on the known order of the cards, the indictments say. The ring also used hidden transmitters and special software to predict the order in which cards would appear, grand jurors alleged.

The three indictments unsealed name 24 defendants, including the son of Seattle Mayor Greg Nickels, in an alleged racketeering enterprise dating from March 2002. The so-called Tran Organization allegedly was based in California.

Interim U.S. Attorney Karen Hewitt in San Diego said the actual losses from the scheme could be much higher than $3.3 million. The losses included $868,000 won in 90 minutes in October 2005 at a Chicago casino.

Casinos in Ontario, Canada, may have lost nearly $2 million (euro1.5 million), said Rob Knudsen, director of the gaming enforcement branch of the Ontario Provincial Police.

Authorities said the scheme targeted 18 gaming parlors in Canada, California, Nevada, Mississippi, Louisiana, Washington state, Indiana and Connecticut. Ten casinos were owned by American Indian tribes.

The scheme involved bribes to casino supervisors and dealers during blackjack and mini baccarat and use of blocks of unshuffled cards, prosecutors contend.

Mayor Nickels said Thursday he and his wife had just learned of the charges against their son.

"We will be encouraging him to cooperate fully with the investigation. Until we know more we will have no comment on the substance of these allegations," Nickels said in prepared remarks.

It was not clear whether any of the defendants had attorneys.

Thirteen other people also were arrested in the same sweep in Ontario and were expected to face charges there, Knudsen said.