HALIFAX -- The disturbing death of a Cape Breton man who was pepper sprayed four times in the face in rapid succession raises concerns about both how guards restrain inmates and the quality of health care afterwards, says Canada's correctional investigator.

Howard Sapers said in an interview his office is delving further into the circumstances surrounding the death of 33-year-old Matthew Hines after the release of a board of investigation report into his death last May following a struggle with guards at Dorchester Penitentiary in New Brunswick.

"When we took a look at the circumstances surrounding his death it raised some concerns ... around the use of force and the medical response to his situation," said the federal watchdog, who has access to full, uncensored accounts of the deaths.

The report prepared for Correctional Service Canada says correctional officers used five blasts of pepper spray, including four administered to Hines' face just seconds apart at about 10:23 p.m. on May 26, after the 33-year-old inmate refused to return to his cell.

The three-person panel says the use of force was inappropriate, noting that Hines was "under sufficient control of the staff" at the time of the repeated spraying.

The report, provided to The Canadian Press by the family, also says that when Hines was taken to a shower to remove the pepper spray, he fell backwards while still handcuffed and with his shirt over his head. As an officer tried to remove Hines' shirt the inmate said, "Please I'm begging you," and kicked with his right leg.

The report says Hines had a seizure at 10:29 p.m. and he was taken to the prison health wing where the nurse "appeared to have conducted no assessments (vital signs, neuro-vitals, oxygen saturation) nor provided any treatment." He was transported to hospital in Moncton and died just after midnight.

Sapers said he is still in the process of investigating, and his office hasn't yet decided whether to issue a public report once its work is complete. He also said he's awaiting a report on the cause of death from the New Brunswick's coroner's office.

The province's Department of Public Safety said the coroner has yet to decide whether to order an inquest into the case that would examine its circumstances and make recommendations.

The details of the struggle with guards and the lack of medical attention has drawn sharp criticism from siblings who say they were initially given scant and inaccurate information about how their brother died.

"We were devastated when we read the report. What he went through, there was no need of it," said Helen MacLeod, Hines' sister, in an interview.

"You wouldn't treat anyone that way."

MacLeod said the family's anguish has been deepened by the hope they'd held out that Hines would receive treatment in the federal prison for drug addiction and undiagnosed mental health issues.

The report says Hines was on parole and staying with his elderly parents when his mother called 911 late on April 18, 2015.

She reported what appeared to them to be a psychotic episode, saying Hines was having hallucinations and was convinced someone was watching him.

Hines was arrested, taken to a provincial facility and then later transferred to the federal prison, where he was serving a five-year sentence for robbery. The report says his prison health care records showed he had abnormal blood pressure and was continuing to receive a medication that can contribute to seizures if taken in excessive amounts.

"In addition to the incident at his parents' home ... Hines had experienced previous incidents of psychotic symptoms and seizures, sometimes simultaneously," says the report.

When guards asked him to leave his cousin's cell on the night of May 26, the report says that Hines made comments such as "Don't let them kill me," and appeared paranoid.

After he refused to enter his cell, guards struggled with the 150-kilogram man, and he was struck several times and kneed as handcuffs were applied, says the report.

Eventually, 13 correctional officers were involved and one delivered an initial blast of pepper spray. As Hines was taken to a segregation unit he received the rapid-fire series of four more blasts of pepper spray to his face.

The report says when they reached the shower cell, with Hines' shirt pulled over his head, Hines repeatedly said, "I'm begging you," "Stop," "No you guys", "Don't" and "at several times what sounded like 'I can't breathe."'

Sapers said his office was aware of 65 non-natural deaths in federal penitentiaries last year, and he has a deepening concern about the instances of poor medical care both before and after the deaths.

"In too many of these deaths we're dealing with people with known mental health disorders ... These people are at risk and it's very disturbing to find those similar sets of facts in so many of these deaths," he said.

"It really does suggest that the Correctional Service of Canada has to make some changes in how it responds to the health needs to ... that part of its population."

A spokeswoman for Correctional Service Canada said that although the agency cannot provide full details regarding Hines' death, it continues to "take concrete steps to address the circumstances surrounding his death."

"CSC officials will continue to cooperate with ongoing investigations and ensure that appropriate follow-up is undertaken," said Laura Cummings.