A Japanese man who spent nearly 50 years on death row before he was acquitted of murder will be compensated 217 million yen ($1.45m), in what his lawyers say is the country?s largest-ever payout in a criminal case.

Iwao Hakamata, 89, was found guilty in 1968 of killing his boss, his boss?s wife and their two children, but was acquitted last year after a retrial.

Mr Hakamata?s lawyers had sought the highest compensation possible, arguing that the 47 years in detention ? which made him the world?s longest-serving death row inmate ? took a toll on his mental health.

Judge Kunii Koshi, who granted the request on Monday, agreed that he had suffered ?extremely severe? mental and physical pain.

The Japanese government will pay Mr Hakamata?s financial compensation, in what local media is widely reporting as the biggest payout for a criminal case in the country?s history.

Mr Hakamata?s case is one of Japan?s longest and most famous legal sagas.

He was granted a rare retrial and released from prison in 2014, amid suspicions that investigators may have planted evidence that led to his conviction.

Last September, hundreds of people gathered at a court in Shizuoka, a city on Japan?s south coast, where a judge handed down the acquittal ? to loud cheers of ?banzai?, or ?hurray? in Japanese.

Mr Hakamata, however, was unfit to attend the hearing. He was exempted from all prior hearings because of his deteriorated mental state.

He had lived under the care of his 91-year-old sister Hideko since being granted a retrial and released from prison in 2014. Hideko had fought for decades to clear her brother?s name.

Mr Hakamata was working at a miso processing plant in 1966 when the bodies of his boss, his boss? wife and their two children were recovered from a fire at their home in Shizuoka, west of Tokyo. All four had been stabbed to death.

Authorities accused Mr Hakamata of murdering the family, setting fire to their home and stealing 200,000 yen in cash.

Mr Hakamata initially denied doing so, but later gave what he came to describe as a coerced confession, following beatings and interrogations that lasted up to 12 hours a day.

In 1968 he was sentenced to death.

For years, Mr Hakamata?s lawyers had argued that DNA recovered from the victims? clothes did not match his, and alleged that the evidence was planted.

Although he was granted a retrial in 2014, prolonged legal proceedings meant it took until last October for the retrial to begin.

The case has raised questions about Japan?s justice system, including the time taken for a retrial and the allegations of forced confessions. (BBC)

?Hakamata, 89, was found guilty in 1968 of killing his boss, his boss?s wife and their two children, but was acquitted last year after a retrial

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