A British court has ruled that one of three men detained over his alleged involvement in a 2015 robbery at a luxury jewelry store in central Tokyo will not be extradited to Japan, citing concerns over the country's human rights record.

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 worth of jewelry. They were put on an international wanted list by Japanese police through Interpol.