Suites in several top hotels were decked out to look like genuine gambling halls with security staff, dealers and other customers as part of the ruse, the South China Morning Post reported.

Customers from mainland China were lured across the border to the southern casino resort and given drinks spiked with drugs before being tricked out of their money, the newspaper said.

One customer lost the equivalent of 1.25 million US dollars while believing he was in a real casino. Police said they had not yet determined the number of victims, but official immigration records showed the gang members had crossed the border into Macau at least 19 times since Mach 2010.

Fake gambling chips worth more than 12 million US dollars were seized in a police raid on a luxury hotel Sunday where the 16 suspects were arrested, according to the Post.

They were charged with fraud, fraudulent gambling and drug trafficking, the newspaper said.

Macau, a former Portuguese colony, is the only place on Chinese soil where casinos are legal. It attracts tens of millions of gamblers a year from mainland China, Hong Kong and Taiwan.