On the 83rd anniversary of the St. Valentine's Day Massacre, Las Vegas celebrated the opening of its newest attraction, The Mob Museum. The city is widely believed to have been built by mob front men while the gangsters sat in the shadows, collecting profits. But when the last of the supposedly mob-owned hotels fell to a pile of rubble to make way for the new mega-resorts on the Las Vegas Strip years ago, many people believed organized crime no longer had any place in the gambling world.

Some recent developments may challenge that notion, however.

MGM (NYSE: MGM) parted ways with the land underneath Atlantic City's Borgata Hotel Casino for a deeply discounted $72 million in 2010. The sale was made after New Jersey casino regulators mandated they either sell their 50% stake in the area's most successful casino, or sever ties with Pansy Ho, their Chinese casino partner and rumored organized-crime boss. They chose Pansy Ho.

A mob of accusations
Just days before the opening of the museum, the SEC launched an informal inquiry into Wynn Resorts' (Nasdaq: WYNN) $135 million donation to the University of Macau in relation to its gaming licenses in the Chinese city. At this time, the SEC will simply review all documents pertaining to the donation and their gaming licenses or renewals in Macau. The inquiry follows a lawsuit by Wynn Resorts board member Kazuo Okada, who alleges he was denied access to documents pertaining to the donation.

Wynn is not the first Vegas casino operator whose Macau operations have been scrutinized by the SEC, either. In March of 2011, Las Vegas Sands (NYSE: LVS) dealt with the SEC looking into possible violations of the Foreign Corrupt Practices Act for allegedly bribing foreign officials. That investigation was connected to a wrongful termination lawsuit from a former employee who allegedly used improper leverage against government officials in Macau.

At this point neither company has been formally charged, and most analysts believe the SEC will find no wrongdoing. But on the off chance that either company is found guilty, fines, jail time, and other legal penalties could be handed down to top managers and directors. With both Steve Wynn and Sheldon Adleson playing very important roles in their organizations, losing one of them would be devastating for shareholders.

Foolish Takeaway
I want to be very clear that in no way am I attempting to persuade anyone to believe that Wynn or Sands has broken the law, nor do I necessarily believe these organizations have committed illegal acts. But the underlying criminal past of the gambling world makes for an interesting backdrop.

To stay informed about how these investigations proceed, I encourage you to add these companies to your Watchlist using the links below. It's free, and will bring you all the relevant news and information about these firms.