term:

Qui Tam Action

qui tam action n

: an action that is brought by a person on behalf of a government against a party alleged to have violated a statute esp. against defrauding the government through false claims and that provides for part of a penalty to go to the person bringing the action [the whistleblower brought a qui tam action against the contractor for presenting fraudulent claims for payment]

Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.