Investigations led by a Republican lawyer named Stuart W. Bowen Jr. in Iraq have sent American occupation officials to jail on bribery and conspiracy charges, exposed disastrously poor construction work by well-connected companies like Halliburton and Parsons, and discovered that the military did not properly track hundreds of thousands of weapons it shipped to Iraqi security forces.

And tucked away in a huge military authorization bill that President Bush signed two weeks ago is what some of Mr. Bowen’s supporters believe is his reward for repeatedly embarrassing the administration: a pink slip.

The order comes in the form of an obscure provision that terminates his federal oversight agency, the Office of the Special Inspector General for Iraq Reconstruction, on Oct. 1, 2007. The clause was inserted by the Republican side of the House Armed Services Committee over the objections of Democratic counterparts during a closed-door conference, and it has generated surprise and some outrage among lawmakers who say they had no idea it was in the final legislation.