WASHINGTON  The Supreme Court on Monday let stand a lower court ruling that the F.B.I. went too far in searching the office of Representative William J. Jefferson, a Louisiana Democrat accused of using his position to promote business deals in Africa.

Without comment, the justices declined to review a ruling by the United States Court of Appeals for the District of Columbia Circuit, which concluded last August that agents had violated the Constitution by the methods it used in the May 2006 search.

The appeals court did not find that the raid itself was unconstitutional; rather, it found that the F.B.I. violated constitutional separation of powers by allowing agents to look freely through Congressional files for incriminating evidence.

The ruling last August told the bureau to return legislative documents to Mr. Jefferson. It did not, however, affect other items seized from his office, including computer hard drives. Nor did it affect evidence seized in a separate raid on the Congressman’s Washington-area home, including $90,000 found wrapped in aluminum foil in frozen-food containers in his kitchen freezer.