Friday's decision not to extradite Joe Chappell, who is currently on bail, was based on the grounds that the Japanese authorities could not provide "sufficient assurances" that he would be treated in compliance with the European Convention on Human Rights. The three men -- Chappell, Daniel Kelly and Kaine Wright -- left Japan two days after the heist, which netted 106 million yen ($731,000) worth of jewelry. They were put on an international wanted list by Japanese police through Interpol. Chappell's defense team has expressed concerns that if extradited, he might be made to confess under duress. Japan has argued that police interrogations in principle are recorded. At a hearing earlier this year, British authorities asked the Japanese government to ensure his detention complies with the convention, particularly on provisions regarding prohibition of torture and the right to a fair trial.