The FBI is investigating the embattled authority overseeing construction of the $6 billion Dulles Rail project, The Washington Examiner has learned.

Federal investigators have spent months looking into contracts worth millions of dollars that were awarded by the Metropolitan Washington Airports Authority to companies that employ friends and relatives of authority officials, sources familiar with the investigation said.

In addition to the FBI probe, an inspector general at the U.S. Department of Transportation is preparing to issue a separate report on its investigation of the authority that is expected detail the agency's history of nepotism, The Examiner has learned.

The airports authority has awarded more than $220 million in contracts without open competition and has spent lavishly on travel, meals and other perks for its top officials, a federal audit of the agency determined in May. Some of those no-bid contracts and other insider deals went to former authority board members and people they knew, The Examiner has reported in a series of articles.

The FBI has been investigating the authority's contracting practices for months and was still interviewing authority personnel this week, a source familiar with the probe said.

An authority spokesman said officials there haven't had "any official contact with the FBI," but did not elaborate.

FBI spokeswoman Lindsay Godwin said she could not confirm or deny the existence of an investigation into the airports authority.

The airports authority, which oversees Ronald Reagan Washington National and Washington Dulles International airports and the $6 billion Dulles Rail project, has endured a flurry of criticism from federal, state and local officials over its handling of the Dulles Rail line, one of the nation's largest public works projects.

The Examiner has reported on a slew of contracts worth hundreds of thousands of dollars that were awarded to former authority board members, including a $180,000-a-year job given to a board member who was quitting for health reasons. The revelations prompted an outcry from state and federal officials, including the nation's top transportation official, Ray LaHood, D.C. Mayor Vincent Gray and the governors of Maryland and Virginia.

In response, the airports authority has adopted new ethics and travel policies and, in August, canceled contracts with former board members.

The authority also was facing criticism -- some of it from its own board members -- for paying the legal bills of a former board member and union executive Dennis Martire, whom Virginia Gov. Bob McDonnell attempted to oust from the board. McDonnell cited Martire's expensive travel and potential conflicts of interest on labor issues. Martire sued but dropped the claim in September and agreed to resign from the board.