An assessment by Canada's spy agency that an Egyptian man might pose a threat to national security is insufficient to keep him detained under stringent house arrest, his lawyers plan to argue Monday.

The release conditions on Mohamed Mahjoub, seen in an undated family photo with his sons, were so stringent at one point that he asked to go back to jail. Toronto Star/CP

They want Federal Court to lift all release conditions imposed on Mohamed Zeki Mahjoub, who has spent the last 11 years in prison or on onerous bail despite facing no charges.

At the very least, the lawyers say, release conditions that include wearing a permanent tracking bracelet should be eased significantly.

In an updated assessment last month, Canada's spy agency warned that Mahjoub could still engage in activities that threaten the security of Canada or another country.

"The service assesses that Mahjoub had, and may still have, connections to" terrorist organizations, the Canadian Security Intelligence Service states. "It remains a possibility that Mahjoub, if released unmonitored and without conditions, may re-engage in activities that constitute a threat to the security of Canada."

Paul Slansky, one of Mahjoub's lawyers, called the assessment too vague to be used as grounds for detention or bail conditions.

"Any such detention or condition must be based upon reasonable grounds to believe that he is a threat to the security of Canada," Slansky said in an interview.

"When you're talking about the 'possibility' that someone 'may' be a threat, that is clearly not reasonable grounds."

Refugee

Mahjoub, 51, who was given refugee status 1996, was first detained in Toronto in May 2000, when Ottawa made him subject to a national security certificate.

The designation allows for indefinite detention without charge or trial of foreign nationals pending deportation, but Mahjoub argues he would be tortured if sent back to Egypt.

The married father of three was released on stringent conditions seven years later.

Mona El Fouli, Mohammad Hahjoub's wife, confronts RCMP officers with her sons Ibrahim and Yusuf outside Prime Minister Stephen Harper's office in Ottawa in June 2006. Tom Hanson/CP

The house arrest was so strict that Mahjoub opted to go back to prison in March 2009 to save his family the burden of their phones being tapped, their house subject to surveillance and narrow limits on who could visit. He was again released after eight months under onerous conditions, but allowed to live in an apartment.

The conditions, which include surveillance of his residence, a curfew and severe restrictions on where he can go, are "among the most invasive in Canadian legal history — prying into every recess" of Mahjoub's life, according to expert submissions to the court.

The conditions have resulted in "irreparable psychological harm" to Mahjoub, his lawyers say.

Based on secret evidence, some of which a judge has found to be derived from torture, CSIS accused Mahjoub of membership in the Vanguards of Conquest, a radical group that merged with al-Qaeda in 2001.

As of last month, CSIS still believed Mahjoub has connections to the groups, even though it concedes it has no information to justify its view, and that he has had no contact with his former associates for at least 15 years.