Media playback is unsupported on your device Media caption Omar Khadr had been held at Guantanamo since 2002, after being detained in Afghanistan aged 15

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 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.

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.

Plea bargain deal

Analysis Omar Khadr's treatment at the naval base has been the subject of a passionate and often polarised debate here in Canada. He has been variously described as a child soldier following orders and a trained radicalised fighter from a family that was part of Osama Bin Laden's inner circle. For many human rights groups, Canadian opposition MPs and other critics, the main sticking points are that Mr Khadr was just 15 at the time of his detention by US military authorities and that, as a Canadian citizen, the government should have demanded his extradition to be tried in Canada, rather than face US military justice in a controversial detention facility. Some of those critics believe that, under international law, Canada had an obligation to provide rehabilitation and counselling services to a minor, regardless of the crimes of which he may have been accused.

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."

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 Khadr's trial, despite federal court rulings in Ottawa that his rights were violated when Canadian agents interrogated him at Guantanamo Bay.

'First family of terror'

Omar Khadr 1986: Born in Toronto

Born in Toronto 1996: Family moves to Jalalabad, Afghanistan, where it allegedly has regular encounters with Osama Bin Laden and other al-Qaeda leaders

Family moves to Jalalabad, Afghanistan, where it allegedly has regular encounters with Osama Bin Laden and other al-Qaeda leaders 2002: Khadr captured during clash between US and Afghan soldiers, and small group of militants

Khadr captured during clash between US and Afghan soldiers, and small group of militants 2007: Charged with murder, attempted murder, conspiracy, providing support to terrorism and spying

Charged with murder, attempted murder, conspiracy, providing support to terrorism and spying 2008: Video shows Khadr being questioned by Canadian officials, and complaining of being denied access to proper medical treatment

Video shows Khadr being questioned by Canadian officials, and complaining of being denied access to proper medical treatment 2010: Pleads guilty and is sentenced to 40 years in prison, reduced to eight

Pleads guilty and is sentenced to 40 years in prison, reduced to eight 2012: Returns to Canada

The majority of Canadians supported the campaign to repatriate 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," Mr 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 paralysed 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 his mother, Maha, are well-known in Canada for their radical views.

Some 166 detainees remain in detention at Guantanamo Bay.