The Supreme Court on Monday denied a Justice Department appeal of a lower court ruling that the FBI raid of Rep. William Jefferson’s (D-La.) office in the Rayburn House Office Building had violated the Constitution’s Speech or Debate Clause.

The decision opens the door for Jefferson to challenge the government’s use of any evidence gathered from his office in the ongoing corruption case against him.

The U.S. Court of Appeals for the District of Columbia Circuit ruled last year that the FBI had violated Jefferson’s rights under the clause by seizing materials from his Congressional office without allowing him to assert privilege over any legislative materials.

The Justice Department argued that it had developed a system for people who were not members of the investigative team to screen the materials that were collected, sifting out legislative from non-legislative materials. The agents removed computer hard drives and two boxes of documents from the office.

But the appeals court ruled that even though the FBI was seeking non-legislative materials, Jefferson had a right to assert the privilege before any materials were viewed by law enforcement agents, hence the search violated his rights.

The dispute over the Rayburn Building raid did not prevent the government from filing its indictment of Jefferson, and the government has indicated that it does not need to wait for a court review of the disputed evidence to continue with its case. The government alleges that Jefferson accepted bribes and payment to help private businesses get contracts in Africa, including accepting cash that was to be used to bribe officials in African nations. Jefferson has denied any wrongdoing.

But Jefferson’s attorneys already have a motion pending before the U.S. District Court in Alexandria to throw out all of the evidence gathered from the search, even if it does not fall within the scope of the privilege, on the grounds that the appeals court has ruled the search illegal.

Beyond the Jefferson case, the Justice Department argued in its plea to the high court that the appeals court ruling “casts doubt on searches of other places and a wide range of other investigatory techniques deemed essential to ferreting out corruption by both members of Congress and persons who deal with them.” Until the Supreme Court overturns that ruling, DOJ argued, “investigations of corruption in the nation’s capital and elsewhere will be seriously and perhaps even fatally stymied.”

— Paul Singer