CANBERRA, Australia (AP) — Australia’s highest court has upheld a law that can keep extremists in prison after they have served their sentences. Five of the seven High Court judges dismissed a constitutional challenge by convicted terrorist Abdul Benbrika, who remains in prison. He is the first extremist to be incarcerated by a so-called preventative detention order based on an anti-terror law created in 2017. Under the law, prisoners convicted of terror offenses can be held for a further three years. The Muslim cleric was convicted in 2009 of being the Melbourne leader and member of a terror cell and his 15-year sentence expired in November last year. Human Rights Watch has warned that such orders could lead to indefinite and arbitrary detention based on little proof.