Photo/Illutration Iwao Hakamada is released from the Tokyo Detention House on March 27, 2014, after spending 47 years and seven months on death row. (Asahi Shimbun file photo)

The Supreme Court overturned a high court ruling that rejected a request by high-profile former death row inmate Iwao Hakamada for a retrial and sent the case back to the high court, paving the way for a possible acquittal.

In the ruling dated Dec. 22, the court's Third Petty Bench withheld judgment on a lower court’s decision to approve a stay of execution and order Hakamada's release, meaning he would unlikely be detained again.

But two of the five justices on the Third Petty Bench opposed sending the case back to the high court, arguing that a retrial should be held instead. Such instances are regarded as highly unusual.

Hakamada, 84, a former professional boxer, was convicted of stabbing four members of a family to death during a robbery and setting fire to their home in Shizuoka Prefecture in 1966. The family operated a miso business that employed Hakamada, who steadfastly maintained his innocence over decades.

An employee found five items of clothing, including a bloodstained half-sleeve shirt and trousers, in a miso tank at the manufacturer’s factory 14 months after the slayings.

A trial in the case was already under way at the Shizuoka District Court.

Shizuoka prefectural police confiscated a strip of cloth that matched the characteristics of trousers at the home of Hakamada's parents.

The judges at the time accepted prosecutors' assertions that the clothing must have been worn by the perpetrator. This was based on a DNA examination of blood stains on the clothes that matched Hakamada's blood type, prosecutors maintained.

Hakamada was handed the death sentence in 1968, which was finalized by the Supreme Court in 1980. He spent decades in detention.

His defense team had long lobbied for a retrial, questioning the credibility of the evidence. The team pointed out that the trousers did not fit Hakamada. They also pointed that the clothing was discovered 14 months after the crime was committed.

His lawyers and supporters provided evidence that led the Shizuoka District Court in 2014 to grant him a retrial and his release after nearly 48 years behind bars.

The Tokyo High Court in June 2018 overturned the retrial order but did not nullify the district court’s decision to approve the stay of execution and order Hakamada's release. His lawyers then appealed the decision to the Supreme Court.