Wei Seng Phua, 50, a suspected organized crime member, and the others were accused in a criminal complaint unsealed minutes before their arraignments in U.S. District Court of participating in the scheme to take bets over WiFi and DSL lines they had casino employees install in their suites at Caesars Palace.
Phua's lawyer, David Chesnoff, was not immediately available before the hearing for comment.
FBI and Nevada Gaming Control Board agents made the arrests Sunday after raids on Wednesday in three Caesars suites. Agents reported finding a laptop computer logging illegal wagers and other records.
The criminal complaint noted that at least some transactions in Las Vegas appeared to have been conducted over a website called "SBOBET."
U.S. Attorney Daniel Bogden said the Las Vegas operation began shortly after Phua left the Chinese gambling enclave of Macau, where he had been arrested June 18 and posted bail on similar allegations of illegal wagering on World Cup soccer games.
Phua is from Malaysia. Bogden identified him as a high-ranking member of the 14K Triad, an Asian organized crime group.
The others arrested were identified as Darren Wai Kit Phua, 22; Seng Chen Yong, 56, and Wai Kin Yong, 22, all of Malaysia; Hui Tang, 44, of China; and Yan Zhang, 40, Yung Keung Fan, 46, and Herman Chun Sang Yeung, 36, all of Hong Kong.
Bogden said that if convicted, each could face up to two years in federal prison on an unlawful transmission count and up to five years in prison on an illegal gambling business count, as well as fines on each count of up to $250,000.
The prosecutor said casino officials co-operated in setting up computer equipment in the three rooms but became concerned that it appeared to be a set-up for an illegal gambling operation.