He has since admitted his involvement with the vanquished Liberation Tigers of Tamil Eelam, and five others involved have been convicted in the US. He came to Australia on a short-term business visa, met and married Priya — a fellow Tamil who had been granted asylum during Sri Lanka’s civil war — and they had a son, Varun. Mr Santhirarajah sought residency but, after his arrest, ASIO gave him an adverse security assessment, meaning he would have had no right to return after his case was finalised in the US.Attorney-General Nicola Roxon approved his extradition to the US in February but Federal Court judge Tony North found the extradition order came two years too late. In a surprise move, Ms Roxon has opted not to appeal, allowing Mr Santhirarajah to leave custody for the first time in four years. An ethnic Tamil who was set to be deported to the US to face terrorism charges, until a judge ruled the commonwealth had bungled the case, is now challenging his adverse ASIO (Australian Security Intelligence Organisation) assessment in a bid to remain in Australia.Thulasi Santhirarajah, the former head of the Melbourne International College, hopes to use a High Court decision last week to build on his own success in the Federal Court and finally be declared a free man. A spokesman for Ms Roxon declined to give reasons for the commonwealth opting not to appeal the Federal Court judgment, other than to say it had sought further legal advice.“Consistent with our bilateral relationship, the decision not to appeal was relayed to the US government,” Ms Roxon’s spokesman said. (The Australian) As his lawyers were last week, challenging the commonwealth’s decision to deny him a visa, the High Court provided a precedent from another case.The High Court ruled that a regulation under the Migration Act was invalid and a 36-year-old Tamil, in detention for almost three years after an adverse ASIO assessment, should have his case reconsidered.At the time, Ms Roxon said the other man would remain in custody while his case was reconsidered and all other cases would be treated on their merits. Mr Santhirarajah, 38, was arrested in 1998 and accused of trying to procure weapons from undercover FBI agents. Lawyers for Mr Santhirarajah are considering their options.