Hans Dalton, 28, was being held in Tafaigata Prison when his body was discovered head-first inside a water drum on Boxing Day 2012.
His cell-mate Jonathan Patrick Crichton, 22, was yesterday acquitted of his murder, after initially being found guilty by the four-person court assessors, or jurors.
Supreme Court Judge Lesa Rapi Va'ai overruled the verdict, citing Section 100 of the Pacific Island nation's Criminal Procedure Act 1972, which gives him the power to do so, the Talamua news website reported.
Judge Va'ai said he would deliver written reasons for his ruling on Friday.
A tearful Crichton - who is serving a life sentence for a 2012 murder - hugged his crying lawyer after the verdict was announced, it was reported. He also hugged Mr Dalton's mother Christine Wilson, as well as Mr Dalton's brother and nephew who had flown from New Zealand to attend the trial.
"Thank God it has ended and I feel strengthened by the court's decision," Crichton is reported as saying afterwards.
Mr Dalton, who had mental health problems, was being held in a Tafaigata Prison cell after becoming aggressive when he lost access to his medication. He had been on holiday in Samoa when the Pacific island nation was hit by a cyclone.
Staff at the hotel he was staying in called for medical assistance but when Mr Dalton could not be calmed, he was taken to the prison.
Prosecutor Precious Chan said Mr Dalton was placed in the cell with two other prisoners, including Crichton, overnight on Christmas Eve 2012. His condition worsened on Christmas Day, and he again became aggressive.
It was in the early hours of Boxing Day that his behaviour grew louder, and he reportedly began swearing, calling out, and punching the door and wall, preventing Crichton from sleeping and riling him into anger, the prosecution case argued.
He was later found head-first inside a 44-gallon drum half-filled with water - used to flush the toilet - inside his prison cell.
Crichton, of Malifa and Tafuna, American Samoa, was being held in custody at the time before going on trial for murder in February 2013.
- Patrice Dougan
