Jeffrey Thompson was for years the go-to money man in District politics, helping candidates for political office in the city to raise hundreds of thousands of dollars.

But on Monday, federal prosecutors indicated that Thompson may have entered their legal cross hairs in connection to a plot to funnel campaign contributions to District politicians. That plot has led to criminal charges against Thompson associate Jeanne Clarke Harris.

Thompson, whom D.C. political consultant Chuck Thies has described as "a behemoth among political donors in the city," has contributed to Mayor Vincent Gray and 10 sitting members of the D.C. Council through a network of family members, friends, employees and business entities.

Many of those lawmakers have received subpoenas in connection with the ongoing investigation into Thompson's activities.

Thompson's connections to city government, however, go beyond his plentiful political donations.

Thompson founded Chartered Health Plan, a managed care company that holds the city's largest contract, one valued at $322 million annually.

He resigned from the company's board in April, about a month after federal agents searched his home and offices. Negotiations about a sale began soon after city officials made clear that the company's contract with the District would be in jeopardy if Thompson remained in charge.

Thompson was also the majority owner of an accounting firm that did significant business with a litany of District government agencies.

Thompson, who rarely appeared in public before the federal probe began, has all but disappeared from the city's political scene. He has not made any contributions to any of the District's campaigns in 2012.