Federal authorities are looking for an inmate who walked away from the U.S. prison camp in southeast Atlanta last week.

The man, Clayton Armstrong Hill, was in prison after being convicted of tax fraud, but he claimed that he was involved in the 1997 shooting death of hip-hop star Christopher “Notorious B.I.G.” Wallace, though he has never been tried in connection with the killing.

Last week, U.S. Magistrate Judge Russell G. Vineyard signed a federal complaint saying Hill walked away from the prison on May 28.

“I was notified by officials … that inmate Clayton Armstrong Hill walked off the grounds,” Deputy U.S. Marshal Clay M. Cleveland said in an affidavit that accompanied the complaint Vineyard signed. “A bed count was conducted to verify Hill’s status, and … Hill was identified as missing.”

The prison camp is a medium-security facility.

Hill was indicted in 2009 and pleaded guilty to filing 121 fraudulent federal income tax returns in Illinois and Georgia between 2002 and 2006, receiving more than $353,000 in refunds, according to the indictment.

In his 2011 prison memoirs, Hill claimed that he was involved in the cover-up of the March 9, 1997, fatal shooting of Wallace in Los Angeles.

An excerpt published in July 2011 by the online magazine HipHopDX described Hill providing hospitality in Atlanta and rides to a man he called the shooter days after the incident, then disposing of the alleged murder weapon.

U.S. marshals continue to search for Hill.