WASHINGTON -- A federal law to prevent U.S. companies from paying bribes to business overseas recently came to the forefront when The New York Times reported that Walmart officials had covered up alleged bribes made by company representatives in Mexico. The retail giant faces federal investigation for violating the Foreign Corrupt Practices Act (FCPA). Wealthy individuals connected with Walmart have meanwhile taken advantage of new campaign finance rules that allow for unlimited contributions -- and raise fears of unlimited influence over a future administration.

Jim and Alice Walton, children of the founder of Walmart, have contributed $200,000 each to Restore Our Future, the super PAC supporting Republican presidential candidate Mitt Romney's campaign. Jim Walton sits on the board of Walmart, and both owe their place near the top of the Forbes list of the 400 richest Americans to their stake in the company.

The Waltons are not alone among super PAC donors with businesses facing FCPA investigation. At least three other major contributors currently have FCPA worries, and others may be looming. The U.S. Chamber of Commerce, another big-money campaign spender, continues its lobbying to loosen enforcement of the anti-corruption law.

Campaign finance watchdogs warn that limitless contributions to super PACs today could influence future priorities at the Department of Justice and the Securities and Exchange Commission, where FCPA investigations originate.

"You've got a whole business community that wants to exercise whatever it takes to maximize their profits," said Craig Holman, Public Citizen's government affairs director. "These are the types of people who want to weaken oversight that would govern fair business practices."

The most notable of the super PAC donors with FCPA concerns is Sheldon Adelson, international casino magnate and eighth richest person in the United States.

Adelson and his family have already contributed $21.5 million to a super PAC that supported Newt Gingrich's presidential bid, $10 million to the pro-Romney super PAC and $5 million to a super PAC with close ties to House Republican leadership. A recent Huffington Post report found that he had given or promised to give $71 million to both super PACs and nonprofits spending money in the 2012 election.

The billionaire's business, Las Vegas Sands Inc., faces three FCPA investigations into casino operations in Macau, China.

Those investigations center on allegations made by the former Sands China chief executive officer, Steve Jacobs, that payments were made by company representatives in Macau to government officials and deals cut with members of the Chinese mafia known as the Triads.

Both the Las Vegas Sands and Adelson have vehemently denied the allegations by his former employee. In an interview with Macau Business, Adelson stated, "When we win the case, we will go after him in a way that he won’t forget because none of what he says is true and he can’t prove it."

Oil tycoons Charles and David Koch, who have promised to spend no less than $100 million to defeat President Barack Obama and place Romney in the White House, have similar legal concerns. Their company, Koch Industries, is under investigation for potential FCPA violations. The company has already fired a host of employees from the European subsidiary involved in the alleged payments to officials in Africa, India and the Middle East.

The computing company Hewlett-Packard is under investigation for alleged payments made by former employees to help a German subsidiary expand into Russia. CEO Meg Whitman and her husband combined to give $200,000 to the pro-Romney super PAC.

Romney supporters are not the only big-money donors with FCPA troubles. While it is not a full-blown investigation, the SEC has opened an inquiry into whether Hollywood studios could be involved in making payments to gain access to the lucrative Chinese movie market, according to CNN Money. One of those studios is DreamWorks, whose CEO Jeffrey Katzenberg has contributed $2 million to Priorities USA Action, the super PAC backing President Barack Obama's reelection, and has raised at least $500,000 for the president's campaign committee.

Watchdogs fear that a future administration, brought to power by these donors, could drop investigations, appoint or hire opponents of FCPA enforcement at the Justice Department and the SEC, or otherwise shift the focus away from FCPA.

"Administrations can set priorities," said Bill Allison, the Sunlight Foundation's editorial director. "They can lower the priority of going after Foreign Corrupt Practices prosecutions. They can spend less on investigations, less on oversight. And they can just send the message that our priorities are this, this and this, and Foreign Corrupt Practices [enforcement] isn't one of them."

Below, more super PAC donors looking to make their mark on the 2012 elections:

PHOTO GALLERY Donors Giving $500,000-Plus To Super PACs