MINNEAPOLIS -- A federal judge says an FBI pornography search was unconstitutional but that the evidence found can still be used against a man from northwest Minnesota.

U.S. District Judge John Tunheim found that FBI agents exceeded the scope of a Virginia search warrant when examining hundreds of computers that were reportedly used to access a secretive child pornography site that once had 150,000 users.

However, Tunheim says there weren't any signs of FBI misconduct during the investigation so he's decided not to throw out evidence being used against Terry Lee Carlson of Coleraine.

Carlson is awaiting trial on more than 10 child pornography charges. He's among more than 900 people arrested in the pornography investigation.