The U.S. attorney's office in Los Angeles in investigating whether the casino company was willfully blind to the transfers of large amounts of money into the casino from a Mexican businessman, who was later accused of drug trafficking, and a former California executive now serving prison time for taking illegal kickbacks, The Wall Street Journal reported.
The probe comes as Las Vegas Sands CEO Sheldon Adelson faces a separate investigation over possible violations of U.S. anti-bribery laws while operating in the Chinese territory of Macau, the Journal said.
Sands spokesman Ron Reese said the company is fully cooperating with federal investigators.
"The company believes it has acted properly and has not committed any wrongdoing," he said.
Investigators are trying to determine if casino executives showed "willful blindness" to the origin of hundreds of millions of dollars transferred into the casino in separate instances by Chinese-born Mexican national Zhenli Ye Gon and former Fry's Electronics Vice President Ausaf Umar Siddiqui whose annual salary was about $200,000.
In order to make a case against the casino, prosecutors will have to prove it overlooked suspicious activity, didn't have an effective anti-money-laundering program or ignored its own policy, the Journal reported.