A man convicted in a 1966 quadruple murder case filed an appeal Monday with the Supreme Court to seek a retrial, his lawyers said, even though he was freed in 2014 after spending nearly half a century on death row.

Former professional boxer Iwao Hakamada, 82, has been struggling to clear his name over the murder in Shizuoka Prefecture, to which he had initially confessed, but the Tokyo High Court on June 11 scrapped a decision by the Shizuoka District Court to grant him a retrial.

Court judgments have been divided over the credibility of DNA tests on five items of clothing said to have been worn by the murderer. The district court concluded that the items were unlikely to be Hakamada's based on an expert analysis provided by his defense team, whereas the high court said that analysis was unreliable.