The death of an inmate at Westmorland Institution earlier this week is under investigation.
John Allain, 70, was found unresponsive in his living unit bedroom on Wednesday, according to a statement issued on Friday by Correctional Service Canada.
Allain was serving a five-year sentence for indecent assault on a female and sexual interference with a female under the age of 14, officials said.
He began serving the term on March 6, 2012.
Correctional officers performed CPR and an ambulance was called, but paramedics were unable to revive Allain, the statement says.
"Correctional Service Canada will review the circumstances surrounding the incident."
Police and the coroner's office have also been notified.
Westmorland Institution is a minimum-security facility in Dorchester.
The campus-style jail houses up to 228 male inmates.