OTTAWA — Federal officials have won a court order to repossess classified national security documents they accidentally gave to a man accused of terrorist ties.

Chanthirakumar Sellathurai was inadvertently given three classified letters from the federal spy agency last August as part of the government's required disclosure of its deportation case against him over the belief he belonged to the outlawed Sri Lakan Tamil Tigers terror group.

The government went to court to get its secrets back and the Federal Court of Appeal has recently ordered them returned and replaced with redacted versions.

But the court sided with Sellathurai's demand he be allowed to contest those sanitized versions because they left a "distorted impression" of the case against him and harmed his lawyer's ability to defend him.

The issue now, is how do he and his lawyer fight what they say is the "overbroad" redaction of information that is once again an official secret?

Disclosing it would be a crime. But when does Canada's open-court principle and an accused person's right to challenge all the state's evidence against them outweigh the public interest of government secrecy?

The strange and protracted case began in 1997 when immigration officials alleged Sellathurai is or was a member of the Liberation Tigers of Tamil Eelam (LTTE) and therefore inadmissible to remain in Canada, according to the reasons for the appellate court decision.

An immigration division admissibility hearing began in 1999. In 2002, with the hearing still in progress, Sellathurai applied for a review of his case by the minister of public safety. The immigration act allows for a reprieve if the minister is satisfied the person's presence in Canada, "would not be detrimental to the national interest."

The Canada Border Services Agency (CBSA) prepared a brief for the minister recommending Sellathurai's request be denied, according to the reasons for the decision.

Sellathurai was provided a copy of the CBSA brief and the opportunity to respond. The immigration division admissibility hearing was adjourned pending a ministerial decision.

More than two years later, in December 2008 and with no word from the minister, immigration officials refused Sellathurai's request for another adjournment.

He responded by going to the Federal Court seeking a judicial review of the refusal, as well a court order staying the unfinished admissibility hearing. The court granted a stay of the immigration hearing and agreed to hear his application for a judicial review.

But in February 2010, the Federal Court adjourned the hearing for a judicial review sine die until a decision was made on ministerial relief.

Six months later, in August 2010, the CBSA disclosed to Sellathurai a new package of information about its position on his case to the minister and a decision was thought to be imminent.

Days later, the agency wrote an urgent letter to Sellathurai's Toronto lawyer, Barbara Jackman. It revealed the new CBSA package contained three classified letters written by the Canadian Security Intelligence Service, "that should not have been disclosed.

"We request that you seal and return the above-noted documents, along with any copies that were made, to our attention at your earliest convenience. We assert that these documents carry national security privilege and must be protected. We thank you for your co-operation in the matter."

Jackman sealed the letters, which were soon put in possession of the court, and wrote to CBSA asking for redacted versions. She added: "I am not sure, if parts of these reports are to be sealed, how we will deal with the fact that he (Sellathurai) and others already have some knowledge of the concerns raised in the documents."

Sellathurai went back to Federal Court and argued the government claim to national security privilege was overbroad because some of the classified material had been previously disclosed during the immigration hearings; that redacting the information was unfair because it left a distorted impression of his case and that Jackman could only make submissions for a ministerial reprieve based on the redacted version; and, even if national security privilege was established, the law does not require that every case of inadvertently disclosed documents be returned.

He also requested a security-cleared lawyer known as a special advocate, or amicus curiae (friend of the court), be appointed to help with his defence. Special advocates are allowed, on behalf of their clients, access to classified information the government wants kept secret so they assist the court and defend their client's interests in closed court hearings.

Sellathurai lost on all fronts. In November, the Federal Court ruled the three CSIS letters were protected under the government's claim of national security privilege and must be returned.

Sellathurai appealed, arguing there is no statutory provision allowing the Federal Court to order the recall of documents already disclosed. He also appealed the court's decision not to appoint a special advocate for his defence.

On July 11, Justice Eleanor Dawson, writing for the three-judge appeals court panel, rejected most of Sellathurai's grounds for appeal.

She did, however, agree the Federal Court judge erred in not appointing him a special advocate and recommended the Federal Court reconsider the issue and, "what, if any, remedy is required by application of the principles of procedural fairness."

She also turned down a government request to return a confidential affidavit it filed with the Federal Court to support its claim of national security privilege.

Jackman did not respond to calls for comment. The CBSA declined to comment, saying the matter is still before the courts. It's believed Sellathurai lives in the Toronto area.