A British court has ruled that one of three men detained over his alleged involvement in a 2015 jewelry robbery at a luxury 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 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.

Japan currently only has extradition treaties with the United States and South Korea. In the absence of an extradition treaty, the country where a crime was committed usually asks a suspect's home country to prosecute.

The three are suspected of taking 46 pieces of jewelry, including rings and pendants after punching a male security guard and breaking display cases at a Harry Winston store in the Omotesando Hills commercial complex in Shibuya Ward on the night of Nov. 20, 2015.

The court has yet to rule on whether to extradite the other two, Kelly and Wright.

Japanese authorities have 14 days to appeal the decision, and another hearing will take place later this month to determine whether the case will continue.