A decade ago gambling magnate and leading Republican donor Sheldon Adelson looked at a desolate spit of land in Macau and imagined a glittering strip of casinos, hotels and malls.

 

Where competitors saw obstacles, including Macau's hostility to outsiders and historic links to Chinese organized crime, Adelson envisaged a chance to make billions.

Adelson pushed his chips to the center of the table, keeping his nerve even as his company teetered on the brink of bankruptcy in late 2008.

The Macau bet paid off, propelling Adelson into the ranks of the mega-rich and underwriting his role as the largest Republican donor in the 2012 campaign, providing tens of millions of dollars to Newt Gingrich, Mitt Romney and other GOP causes.

Now, some of the methods Adelson used in Macau to save his company and help build a personal fortune estimated at $25 billion have come under expanding scrutiny by federal and Nevada investigators, according to people familiar with both inquiries.