A federal appeals court on Wednesday temporarily delayed a Justice Department bribery investigation of a Louisiana congressman while he challenges the legality of an unprecedented FBI raid on his Capitol Hill office.

The decision by two members of a three-judge panel means the Justice Department cannot begin a review set to begin Wednesday of more than a dozen computer hard drives, several floppy discs and two boxes of documents seized during a May 20-21 raid on Democratic Rep. William Jefferson's Rayburn Building office.

"The purpose of this administrative injunction is to give the court sufficient opportunity to consider the merits of the motion for a stay pending appeal and should not be construed in any way as a ruling on the merits of that motion," wrote Judges Janice Rogers Brown and Thomas B. Griffith of the U.S. Court of Appeals for the D.C. Circuit. The identity of the third judge is not known.

Attorney General Alberto Gonzales had set a Wednesday deadline to allow a special review team of prosecutors and FBI agents to begin culling through the evidence seized during the controversial raid on Jefferson's office.

The overnight search — which lasted 18 hours — was part of a 16-month international bribery investigation of Jefferson, who allegedly accepted $100,000 from a telecommunications businessman, $90,000 of which was later recovered in a freezer in the congressman's Louisiana home.

Jefferson's appeal challenges a ruling earlier this month by Chief U.S. District Judge Thomas F. Hogan, who upheld the legality of the raid, saying that barring searches of lawmakers' offices could turn Capitol Hill into "a taxpayer-subsidized sanctuary for crime."

According to a government court filing last week, Jefferson also is under investigation in "at least seven other schemes in which the congressman sought things of value in exchange for his performance of official acts."

Jefferson wants the appellate court to allow him to look at the seized materials before the special review team to determine whether any of the documents fell into the category of legislative privilege.

But the Justice Department opposes allowing a congressman to screen evidence that could be used against him. Instead, the department has agreed to give copies of all the seized materials to Jefferson so he can then raise objections with a judge about their use in the investigation.

In his ruling, Hogan rejected requests from Jefferson and a bipartisan group of congressional leaders to return the seized materials, saying the raid did not violate the Constitution's protections against intimidation of elected officials.

At issue is a constitutional provision known as the speech or debate clause, which protects elected officials from being questioned by the president, a prosecutor or a plaintiff in a lawsuit about their legislative work.

Investigators had held off on reviewing the records because the outcry on Capitol Hill after the raid was loud enough for President Bush to order the solicitor general to take custody of the seized materials until Congress and the Justice Department could work out procedures for future raids on congressional offices.

Jefferson has been under investigation since March 2005 for allegedly using his position to promote the sale of telecommunications equipment and services offered by iGate, a Louisville-based firm, that sought contracts with Nigeria, Ghana and other African nations.

In return for his help, Jefferson allegedly demanded stock and cash payments. Jefferson has not been charged and has denied wrongdoing.