The transactions date from the mid-2000s.
The Journal said there are no indications that actions by Adelson, the company’s chief executive and largest shareholder, are being investigated.
The Los Angeles U.S. attorney could not be reached for comment by Reuters on Saturday. A Sands spokesman was not immediately available to comment to Reuters, but spokesman Ron Reese told the Journal, “The company believes it has acted properly and has not committed any wrongdoing.”
Reese said the company was cooperating with federal investigators.
The timing of the investigation could open the Justice Department to criticism that it is politically motivated, the Journal said. Adelson is a major donor to the super PAC supporting presumed Republican presidential nominee Mitt Romney against President Obama and plans to spend $100 million on Republican candidates in November’s elections.
Adelson, who owns casinos in Las Vegas, Macau and Singapore, began this campaign season as a major donor to Newt Gingrich before Gingrich dropped out of the Republican presidential race. He has since switched his support to Romney and last month was in Jerusalem with the candidate when Romney met Israeli Prime Minister Benjamin Netanyahu, who Adelson also strongly supports.
The Journal said the Las Vegas money-laundering investigation focused on two “whales” — as big-money gamblers are known — and whether Sands officials ignored warning signs and did not alert federal authorities about millions of dollars the gamblers had deposited.
The Journal identified one of the “whales” as Zhenli Ye Gon, a Chinese-born Mexican national who was indicted in 2007 in the United States on charges of dealing in materials used to make methamphetamine.
The drug case was dismissed in 2009 but Ye Gon is still in U.S. custody awaiting extradition to Mexico, where authorities want to try him on drug trafficking and money laundering charges, the Journal said, citing court records.
The Journal said Ausaf Umar Siddiqui, a former executive with the Fry’s Electronics retail chain, also was under scrutiny. Court filings in another case showed Siddiqui sent more than $100 million to the Sands. Siddiqui was charged with taking kickbacks from Fry’s vendors, pleaded guilty and is now in prison.
U.S. authorities also are investigating the Sands to see if there were breaches of the Foreign Corrupt Practices Act, which prohibits bribes to foreign officials by U.S. companies, in its Macau operation.