LEWISTON – Convicted killer Brandon Thongsavanh was accused over the weekend of stabbing another inmate at the state prison in Warren.

Prison officials and other agencies are investigating a claim that the 23-year-old Lewiston man stabbed another inmate in the chest and leg with a homemade weapon. The victim, who has not been identified, is expected to survive his wounds.

Investigators are reviewing footage from video surveillance cameras and speaking with other prisoners as charges against Thongsavanh are being considered, according to prison Warden Jeffrey D. Merrill.

Thongsavanh is serving a 58-year prison sentence for the March 2002 stabbing death of Bates College senior Morgan McDuffee. In that attack, which happened during a street fight on Main Street in Lewiston, McDuffee was stabbed five times, including once in the heart, prosecutors said.

Thongsavanh’s lawyers are appealing the prison sentence, which was handed down after he was tried for a second time on the murder charge.

For roughly a year, while awaiting retrial, Thongsavanh was sent to a prison in Arizona as part of a prisoner exchange deal. Jail officials in Maine said that while he was being held in Arizona, Thongsavanh was an enforcer for a group of inmates and was involved in an incident during which another prisoner’s throat was slashed.

In the latest incident in Warren, investigators said they have been told that Thongsavanh lured another prisoner to his cell and stabbed him after a dispute. Prison officials Monday did not discuss details of that dispute or what may have led to the attack.

Had the victim died, the Attorney General’s Office would have handled the prosecution. Instead, any charges against Thongsavanh will be handled by the District Attorney’s Office in Knox County.

District Attorney Geoffrey Rushlau would not discuss details of the case while it is under investigation. In cases of prison crime, suspects are not immediately arrested. Instead, prison officials investigate a case and leave it up to the district attorney as to how to proceed with prosecution.

“They complete their investigation and forward their findings to us,” Rushlau said.

It is unclear how or if the incident will affect Thongsavanh’s latest appeal of his sentence. His lawyers have claimed that the jury that convicted him should have been given the option of finding him guilty of criminally negligent manslaughter instead of murder.

Thongsavanh’s lawyers, Scott Lynch and David Van Dyke, could not be reached Monday for comment about the latest accusations.