The court ordered the return of some of the documents seized in the raid.

"We hold that the compelled disclosure of privileged material to the executive during execution of the search warrant for Rayburn House Office Building Room 2113 violated the Speech or Debate Clause," the court said.

The decision applies only to privileged documents -- those on legislation -- and not to all the materials taken in the raid.

The Louisiana Democrat is under indictment for taking thousands of dollars from a telecommunications company seeking contracts in Africa.

The unprecedented raid angered congressional representatives from both parties. Agents also searched Jefferson's homes in Louisiana and Washington, finding thousands of dollars in a home freezer.