A Canadian who says he was unfairly imprisoned in Ethiopia in abysmal conditions for more than a decade wants an independent review of Ottawa's actions in his case.

In his first public comments since being released, Ethiopian-born Bashir Makhtal said Tuesday there were mistakes and lost opportunities in Canada's efforts to protect him over the years.

"I have to start my life all over again," Makhtal told a news conference as his wife Asiso looked on.

He was accompanied by lawyer Lorne Waldman and Alex Neve, secretary general of Amnesty International Canada, who fought for years to secure his release.

Makhtal moved to Somalia as a youngster to attend school and settled in Canada as a refugee in 1991. He later moved back to Africa, opening a used-clothing business to help support his family. Makhtal was working in Somalia when Ethiopian troops invaded in late 2006.

He fled back to Kenya, but was detained along with several others at the Kenya-Somalia border.

Makhtal was later convicted of terrorism-related charges in Addis Ababa -- proceedings Waldman has denounced as a "kangaroo court" that ignored important evidence.

Makhtal, 49, was suddenly freed last month, a development Waldman attributes to Prime Minister Justin Trudeau's intervention in the case.

Makhtal's ancestry is rooted in the Ogaden people of Ethiopia, who are ethnically Somali. His grandfather, who pushed for greater rights and protection for the minority, was imprisoned and subjected to house arrest.

As a result, Makhtal was worried in early 2007 when two Ethiopian security agents came to question him alongside Kenyan officials.

"I had not been back in Ethiopia since I left when I was seven, and did not trust the Ethiopian officials at all."

Makhtal alerted Canadian officials in Kenya. They came to see him three or four times, but they only wrote two letters of concern to the Kenyan foreign ministry, he said, and his case was not raised at more senior levels.

Makhtal said he was whisked from his cell on a Saturday, taken to the Nairobi airport and beaten when he refused to board an aircraft. "I was then tied up, blindfolded and forced into the plane."

He and dozens of others wound up in Addis Ababa.

Makhtal said he was held in solitary confinement in a damp, underground cell measuring two metres by two metres.

He was interrogated repeatedly. "Their aim was to encourage me to become a collaborator with the Ethiopian government to spy on the Ogaden people," he said. "I constantly said I had done nothing wrong and that I would not turn against my people.

"They threatened to go after my family as well, which they did."

In mid-2007, Makhtal's brother and his son, his sister and her son, and other family members were also arrested.

When his brother Hassan was finally released in 2009, his health was so poor -- including infection from a broken rib that had punctured his lung -- that he died only a few days after he was freed.

Makhtal's nephew, arrested as a teenager 11 years ago, remains behind bars.

On the morning of April 18, a prison official whispered in Makhtal's ear that he was to be freed. Forty-eight hours later he was on a flight back home to Canada.

Former Conservative foreign minister John Baird made efforts on Makhtal's behalf. Waldman, however, said Stephen Harper, who was prime minister at the time, refused to get involved.

"What's notable about Bashir's case is that Prime Minister Trudeau took a different attitude and intervened directly, and it was after that intervention that Bashir was released," he said.

"So I think that's an important fact. The role of the prime minister in these complex consular cases is crucial."

When Makhtal was detained in Kenya, Canadian officials should have flagged the matter to Ottawa, and headquarters should have approached the Kenyan ambassador, Waldman said. "The Kenyan officials didn't have any sense that Canada was concerned, and that's why they were able to get away with what they did."

Waldman called on the Canadian government to help free Makhtal's nephew.

He said Ottawa should also establish an independent review of Makhtal's case that includes access to relevant documents and witnesses.

An examination would help highlight the "many important lessons to be learned here," Neve said.

Parliamentary secretary Omar Alghabra, who met with Makhtal in Ethiopia, spoke with him again Tuesday, said Adam Austen, spokesman for Foreign Affairs Minister Chrystia Freeland.

The government is "always looking for ways to improve Canada's consular services," Austen said in a statement.

"This includes listening to recommendations on consular services from Canadians who have faced difficulties abroad -- as Mr. Alghabra is doing today -- as well as to views from civil society."