Michael Higginbottom was found guilty on five counts of serious sexual assault and seven counts of indecent assault, leading to his imprisonment for 18 years in July 2019.
The victims were abused by him while boarding at St Joseph's College, a now-closed Catholic seminary in Upholland, near Skelmersdale, during the 1970s and 80s.
Higginbottom, who taught at the seminary, was convicted after a retrial. A court heard he 'carried out a series of violent sexual assaults' and used a strap or a belt to hit the boys.
The Prisons and Probation Ombudsman (PPO), which investigates all prison custody deaths, has now published its report after his death in June, 2022, while a prisoner at HMP Stafford. Higginbottom, says the report, died in hospital from a bleed on the brain. He was 79, reports the M.E.N.
Higginbottom was admitted to hospital with a stroke on February 1, 2022. He was discharged 10 days later and spent the next three months in the prison's Specialist Care Unit (SCU).
Higginbottom was returned to a standard wing on May 11. The report, however, says prison staff 'struggled to meet his care needs'. On May 24, 2022, staff found Higginbottom 'unresponsive' and he returned to hospital, where he died less than two weeks later.
Kimberley Bingham, Acting Prisons and Probation Ombudsman, said in her report: "The clinical reviewer found that the care Mr Higginbottom received in the prison's SCU was good and was equivalent to that which he could have expected to receive in the community.
"However, I am concerned that Mr Higginbottom's care needs were not met when he returned to a standard wing and I consider that the prison could have done more to explore alternative options for him."
Higginbottom was said to have had several long-term health conditions, including high blood pressure and heart disease. He also had poor mobility and signs of memory loss, adds the report.
The report says prison staff found Higginbottom 'unconscious and unresponsive' on his bed in his cell. He died in hospital on June 5, 2022. A coroner concluded he died from natural causes after an inquest.
Judge Andrew Woolman, sentencing Higginbottom in court, told him: "You were in the highest position of trust in relation to these boys, who you abused in a quite appalling way.
"I have no doubt that you specifically targeted these boys. These acts were accompanied, time after time, by threats or actual violence under the guise of a normal school punishment. The way you acted left them with a sense of shame and of guilt, as well as the sense that no-one would believe them if they complained."