A U.K. prisons watchdog's report highlights the case of an 84-year-old Canadian man who died while handcuffed at an immigration removal centre in Britain last year.

The man was sent to the Harmondsworth immigration removal centre on January 23, 2013, after he was refused entry to the country at Gatwick Airport, the report revealed.

Describing the "very concerning case," the report released by Her Majesty’s Inspectorate of Prisons Thursday notes, "detention seemed to have been used as an inappropriate default for a man who required social care."

The report goes on to cite a doctor's report in which the man is described as frail and suffering Alzheimer's disease.

He was not released, however, and his case was never referred to social services for assessment.

"The on-site immigration team had also expressed their concerns to the caseworker," one week later, according to the report. But a caseworker did not report the man's vulnerability, and lack of contacts in the U.K., until February 5.

A subsequent attempt to send him back to Canada was called off after a doctor deemed the man unfit to fly.

Instead, he was transferred back to the immigration centre in handcuffs.

"He had been in handcuffs for approximately five hours when he died, still wearing them," according to the report.

"Only after his heart had stopped and cardiopulmonary resuscitation started were the handcuffs removed."

While the report does not name the Canadian, he is identified in media reports as Alois Dvorzac.

The report cites other shocking cases, including that of another man who died shortly after his handcuffs were removed.

"These men were so ill that one died shortly after his handcuffs were removed and the other, an 84 year-old-man, died while still in restraints. These are shocking cases where a sense of humanity was lost," the HM Inspectorate of Prisons writes in the report spurred by the findings of surprise inspections at Harmondsworth last August.

Britain's Prisons and Probation Ombudsman is now preparing to investigate the Canadian man's death, and the West London Coroner is undertaking an inquiry.

The removal centre, which is located near Heathrow Airport, is run by private contractor GEO Group UK Ltd.

Harmondsworth and other similar centres in Britain are used to house people who have been denied entry into the country, but are refusing to leave.