(09-10) 17:03 PDT SAN JOSE - A computer expert who served as a confidential source for an elite FBI computer crime squad has been arrested on wire-fraud charges, five years after being released from federal prison for hacking into government computers.

Max Ray Butler, 35, also known as Max Vision, was arrested Wednesday on a federal arrest warrant issued in Pennsylvania, authorities said. He was charged a day earlier with wire fraud, identity theft and access-device fraud.

The alleged crimes happened from October through December in Allegheny County, Pa. Further details of the case were unavailable, as the affidavit from a U.S. Secret Service agent that accompanied the criminal complaint remains under seal.

Butler is to appear Tuesday before U.S. Magistrate Patricia Trumbull in San Jose for a detention hearing.

Butler was released from federal prison in October 2002 after being sentenced to 18 months and ordered to pay more than $60,000 in restitution for computer hacking. He was indicted in 2000 on charges of hacking into computers used by UC Berkeley, national laboratories, federal departments, Air Force bases and a NASA flight center in 1998.

Butler grew up in Idaho and lived with his family in Washington, where authorities said he has a 1997 misdemeanor conviction for attempted trafficking of stolen property.

He developed a proficiency with computers, eventually attracting the attention of the FBI's Computer Crime Squad, which used him as a confidential informant.

But at his sentencing in 2001, a federal prosecutor said Butler "masqueraded as an informant for the FBI," claiming to be cooperating with the agency while using computer programs that conducted automated, unauthorized system attacks.

An FBI search warrant affidavit in 2000 said Butler was "well known" to squad members and "has provided useful and timely information on computer crimes in the past."

In 1997, Butler started a company known as Max Vision in Mountain View, specializing in "penetration testing" and "ethical hacking" procedures in which he would simulate for clients how a hacker would penetrate their computer systems, according to the company Web site.