OTTAWA - A lawyer for terror suspect Mohamed Harkat says his client's alleged declaration of loyalty to an Algerian extremist group -- even if true -- hardly makes him a member.

The Canadian Security Intelligence Service claims Harkat, arrested in Ottawa more than seven years ago, has ties to Islamic extremists and that he professed loyalty to Algeria's Armed Islamic Group.

Lawyer Matt Webber told a CSIS officer during a Federal Court hearing Thursday it's hard to know what that means without more information and context.

Under cross-examination, the CSIS officer, referred to only as John to shield his identity, said the point is significant because it indicates Harkat's support for the methods of an "incredibly violent terrorist organization" known for killing civilians.

However, John could not elaborate, noting any information to underpin the allegation would be classified.

The government is trying to deport Harkat under a national security certificate, a rarely employed immigration provision for removing suspected terrorists and spies.

CSIS says Harkat has displayed behaviour typical of "sleeper" agents who set themselves up in foreign countries -- use of a false passport and aliases, keeping a low profile and concealing his previous whereabouts.

The former gas-station attendant and pizza delivery man, arrested in December 2002, denies any involvement with terrorism.

The Algerian-born Harkat, 41, arrived in Canada in 1995, obtained refugee status and applied for permanent residence.

In his refugee claim, he acknowledged support for Algeria's Islamic Salvation Front, or FIS, a legitimate political organization when he became involved in the late 1980s. After the Algerian government cracked down on the FIS, Harkat went into hiding and moved to Pakistan.

CSIS contends that when the FIS severed its links with the Armed Islamic Group, or GIA, Harkat indicated his loyalties were with the GIA.

Justice Simon Noel is presiding over public hearings expected to last six weeks, and will decide whether to uphold or quash the security certificate.

Noel and federal counsel are privy to classified details of the case, but Harkat and his defence team are working only with a public summary of the evidence.

Harkat, who remains under strict bail conditions, has attended the hearings daily, sitting in the public gallery with wife Sophie.

Harkat says he worked for the Muslim World League, a charitable relief organization, for four years in the early 1990s, distributing rice, oil, flour and clothes to the needy in Pakistan.

CSIS contends Harkat is not telling the truth about his activities in Pakistan, nor concerning his association with Ahmed Said Khadr, a now-deceased Canadian aid worker who had ties with al-Qaida leader Osama bin Laden.

Khadr's son, Omar, is detained at a U.S. prison in Guantanamo Bay, Cuba, on charges he threw a grenade that killed a U.S. soldier in Afghanistan.

Detailed information about allegations that Harkat worked for Human Concern International, the Ottawa-based charity that employed Ahmed Said Khadr -- and carried out tasks on Khadr's behalf -- remains under wraps.

When Webber pressed for more details about the accusation, Noel said everything that could be disclosed publicly is on the record.

"If we could have said more, we would have done so," the judge said.

"He knew him well enough to be entrusted by Mr. Khadr to assume specific tasks."

Harkat has acknowledged only meeting Khadr in passing in Canada.