One of two men convicted of chaining and sexually assaulting a 16-year-old boy in a Nova Scotia cabin has died in prison, apparently from natural causes.

John Leonard MacKean, 65, had served less than two months of his two-year prison sentence when he died at the Springhill Institution in Nova Scotia, CTV Atlantic’s Kayla Hounsell reported Thursday.

Springhill officials said it appears that MacKean died from natural causes. His lawyer, Mike Taylor, said MacKean had significant health issues and was being held in protective custody, Hounsell reported.

MacKean was convicted in March of sexual assault and communicating for the purpose of obtaining sexual services from a person under 18. He was sentenced in June.

Two other men were involved in the case that police investigators described as horrifying.

David James LeBlanc pleaded guilty to kidnapping, forcible confinement and sexual assault and was sentenced to 11 years in prison. A third man involved in the case died before he was arrested.

The boy was held captive for eight days in a remote cabin in 2012. MacKean had admitted to a sexual encounter with the boy, but denied knowing how old the victim was.

After MacKean’s sentencing hearing, the boy’s mother said the convict had “no remorse” and expressed outrage that he was only sentenced to two years in prison.