A 60-year-old man has been sentenced to 25 years in prison in the prison death of former cult leader Roch Thériault.

Once described as Canada's Charles Manson, Thériault was found dead near his cell at New Brunswick's Dorchester Institution on Feb. 26.

Police say the 63-year-old got into an altercation with fellow inmate Matthew Gerard MacDonald inside the correctional centre.

Thériault died as a result of his injuries and MacDonald was originally charged with first degree murder in his death.

MacDonald, of Port au Port, Newfoundland pleaded guilty to second degree murder today in Moncton provincial court.

He will have no eligibility for parole for 25 years.

Thériault founded and led a notorious sect in the 1980s. It was first established in two Quebec towns, Saint-Marie-de-Beauce and Saint – Jogues, then finally in Burnt River, Ontario.

He was sentenced to life in prison in 1993 for the gruesome murder of this wife, Solange Boilard, who was killed with a kitchen knife as part of a cult ritual.

MacDonald was serving time for two deaths in British Columbia at the time of Thériault's death.