Canada is "extremely disappointed" with reports that a Canadian was tortured while in a Bahrain prison and has asked the Bahraini government to review his case, a cabinet minister says.

Naser al-Raas, 29, was the only one of 13 defendants convicted on Oct. 25 for charges of illegal assembly, rioting and incitement. He was sentenced to five years in prison. He alleges he was tortured in prison and has gone into hiding after losing an appeal Tuesday of his conviction.

Canadian Naser al-Raas, who alleges he was tortured in a Bahrain prison, lost his appeal of his conviction for participating in the Arab Spring protests. (Family photo)"I saw how bad they tortured people, and even I witnessed an innocent man — he was tortured until he passed away and he was next to me," al-Raas told the CBC's Ashley Burke via Skype. "I think if I will be in custody again, they will get their revenge."

After learning the five-year sentence had been upheld, Diane Ablonczy, the minister of state of foreign affairs (Americas and consular affairs), said in a statement Canada was "extremely disappointed with the recent reports regarding Mr. Al-Raas' sentence and are following up with Bahrain officials on the matter."

Canada 'deeply concerned' about situation

"We remain deeply concerned about Mr Al-Raas' situation in Bahrain," Ablonczy said. "We call on the Bahraini government to review the case in light of the recommendations of the Bahrain Independent Commission of Inquiry to ensure, among other things, free political expression and protection from arbitrary detention. Canada hopes to see these recommendations applied in the case of Mr. Al-Raas."

Al-Raas had been living and working in Kuwait but went to Bahrain in April to visit his sisters and fiancée. He was then accused of joining ongoing demonstrations.

He said he was arrested when he was about to board a plane to return to Kuwait at the Bahrain International Airport. His passport was confiscated and he was taken to Al Qala prison.

Al-Raas, a Kuwait-born Canadian citizen and former Ottawa resident, fears he will die in custody if he continues to serve the five-year sentence.

Passport, ID confiscated

Al-Raas has claimed he was tortured for a month last year for a similar offence. He still wants all charges dropped. The authorities have also confiscated al-Raas's passport and other identification.

He also said he will be deprived of medication he needs for a heart and lung condition.

Ablonczy said Canadian officials continue to press for the case to resolved quickly, particularly in light of "Mr. Al-Raas grave health concerns."

Last fall, Al-Raas had criticized the Canadian government for observing his trial but not doing enough to help him.