Omar Khadr, the youngest prisoner to be held at the Guantanamo Bay detention centre, has been returned to his native Canada.

Omar Khadr had been held at the US base in Cuba since 2002, after being detained in Afghanistan aged 15.

A military plane flew Omar Khadr, the last Westerner at Guantanamo, to Canada early on Saturday.

He will serve the rest of his eight-year jail term in Canada. He pleaded guilty to killing a US soldier in Afghanistan.

Omar Khadr left the prison on a US military plane and arrived at a Canadian air base in Trenton in Ontario province, from where he was transferred to the Millhaven maximum prison, Public Safety Minister Vic Toews told a news conference.

The US Department of Defense said in a statement: “The United States government has returned Khadr to Canada where he will serve out his remaining sentence. The United States co-ordinated with the government of Canada regarding appropriate security and humane treatment measures.”

Omar Khadr was sentenced to 40 years in prison by a US military tribunal at Guantanamo Bay in 2010 on war crimes charges.

The charges against him were: murder in violation of the law of war; attempted murder in violation of the law of war; conspiracy; providing material support for terrorism; and spying.

But as part of his plea deal, his sentence was limited to eight years.

Under the deal, he became eligible to return to Canada last October.

Canada declined to intervene in Omar Khadr’s trial, despite federal court rulings in Ottawa that his rights were violated when Canadian agents interrogated him at Guantanamo Bay.

The majority of Canadians supported the campaign to repatriate Omar Khadr, now 26, though the country remains split over the case.

“Omar Khadr is a known supporter of the al-Qaeda terrorist network and a convicted terrorist,” Vic Toews said on Saturday.

Many still consider him and some members of his family a threat, while others see him as a child victim of both an extreme Islamist ideology and cruel and unusual treatment at the hands of the US authorities.

The Khadrs have been called Canada’s “first family of terror”.

Omar Khadr’s father, an associate of Osama Bin Laden, took the family to Peshawar, in Pakistan, to support the Afghan mujahideen in their war against the Soviets when Khadr was a child. The father died in a firefight with Pakistani troops near the Afghan border in 2003.

One brother is paralyzed from the waist down after being wounded in that same battle. Another has just been released from jail in Toronto after successfully fighting extradition to the US on terror charges.

Omar Khadr’s sister Zaynab and mother Maha are well-known in Canada for their extremist views.

Some 166 detainees remain in detention at Guantanamo Bay.