Former Alouette Lawrence Phillips, who helped Montreal win the Grey Cup in 2002, is suspected of killing his cellmate in a Central California prison, officials said Monday.

Phillips' cellmate at Kern Valley State Prison was found lifeless early Saturday and later pronounced dead, prison spokesman Lt. Marshall Denning said in a statement

He is suspected of killing Damion Soward, a 37-year-old inmate from San Bernardino County serving 82 years to life for a first-degree murder conviction.

A second inmate also under suspicion for the murder.

Phillips, 39, was once one of the nation's top college football players at Nebraska. He played for the St. Louis Rams, until being released in 1997 for insubordination. He also played for the Miami Dolphins and San Francisco 49ers.

Montreal handed Philips the starting running back job over Mike Pringle who was only the all-time leading rusher in CFL history.

Phillips rushed for over 1000 yards, averaging 5.5 yards per carry. He did not return the next year and only played a few games with Calgary in 2003.

Phillips is already serving a 31-year-sentence after being convicted of choking his girlfriend in 2005 in San Diego and driving his car into three teens after a pickup football game in Los Angeles.

Prison officials said they suspect a second inmate at the prison of killing his cellmate. It's unclear if the two are related.

John Munoz, a 24-year-old sentenced to 42 years on for sexual battery and other charges in Los Angeles County, is suspected of killing cellmate, 41-year-old Rattanak Kim, who was serving a sentence of 35-years to life for conspiracy to commit murder in San Diego County.

Prison officials are investigating both deaths along with the Kern County Coroner and Kern County District Attorney, prison officials said.

-With files from The Canadian Press and The Associated Press