US law enforcement officials say they have dismantled a global cocaine and money-laundering hub involving more than 30 other countries including Australia, Canada and the UK.
The investigation began six years ago in Las Vegas but did not arise from a casino-related probe.
The top federal prosecutor and the FBI chief in Las Vegas told reporters on Wednesday the probe became public after the recent arrests of six people in Nevada, Arizona, California and Washington state on conspiracy, drug and money-laundering charges.
Acting US Attorney Christopher Chiou and Aaron Rouse, special agent in charge of the Las Vegas office, were flanked by representatives of law enforcement agencies in Australia, Canada, Colombia, Costa Rica, Israel, Romania and the UK.
The FBI chief said millions of dollars were involved, but he wouldn't specify an amount.
He characterised the conspiracy as a "cog" in a drugs-and-money operation supporting "trans-national" criminal organisations that he said will be crippled by the six arrests and "dozens" of others in other places in the six-year operation dubbed "Operation Money Maker."
Rouse declined to provide exact numbers, places or details of those cases.
"Take the cog out, the spokes fall," he said. "Their hub is gone."
Chiou said two of the six people named in separate indictments being unsealed are Las Vegas residents. Others are from Los Angeles, Seattle, Phoenix and San Jose, California.
The five men and one woman range in age from 31 to 51. Each will be prosecuted in Las Vegas, Chiou said. Each is a US citizen and faces a conspiracy charge.
Three face additional drug distribution charges and four of the six are accused of money laundering. Each could face decades in prison if convicted.