A former spy-agency watchdog has been given the job of fighting Ottawa's attempts to shield its secrets from public view once the Arar commission begins its fact-finding mission next month.

Ron Atkey is known as an outspoken critic who has frequently butted heads with the RCMP and the Canadian Security Intelligence Service, the two agencies that will be scrutinized most during the inquiry.

Mr. Atkey, a Progressive Conservative cabinet minister during the 1970s and chair of the Security Intelligence Review Committee during the 1980s, was appointed a friend of the court yesterday by Arar commissioner Mr. Justice Dennis O'Connor.

His job will be to aid Judge O'Connor in helping the public understand how Canadian officials may have contributed to the detention of Maher Arar.

Mr. Arar is a 33-year-old Syrian-born Canadian who was branded a terrorist by U.S. guards who deported him to his homeland after he arrived at a New York airport in 2002.

For nearly a year, Mr. Arar was jailed in Syria as an al-Qaeda suspect, only to return to Canada a free man who described being tortured.

Like Mr. Arar, two other Arab Canadians acquainted with him were also investigated in Ontario prior to being separately detained in the Middle East. They say they suffered identical fates in Syria although, unlike Mr. Arar, they had travelled there of their own volition.

Mr. Arar, his wife Monia Mazigh, and human-rights groups aggressively lobbied for a public inquiry into his detention. After the Canadian government granted it this winter, the other two detained men, Ahmad Abou El-Maati and Abdullah Almalki, were released from Middle Eastern jails. Though they have been denied formal standing at the Arar commission, they are expected to be called as witnesses.

Because all of this involves secretive security information being swapped by Canada, the United States, Syria and other countries, Ottawa is expected to seek to shield much of the proceedings from public view.

Government lawyers have already strongly signalled they will not allow Canada's national-security secrets and its ongoing investigations to be compromised. It will be Mr. Atkey's role to try to rebut such arguments, and to keep matters as transparent as possible as the government seeks to take the proceedings behind closed doors.