AUDIO recordings on board the so-called "death ship" where three crew members died or disappeared within six weeks were most likely deliberately deleted, a coronial inquest has been told.
And the shipping company's executive director failed to tell Japanese authorities there could be a link between the fatalities.
The Sydney inquest into chief cook Cesar Llanto's disappearance and the death of chief engineer Hector Collado on one of the world's largest coal ships, Sage Sagittarius, has heard it was "very likely" crucial audio recordings from the ship's voyage data recorder had been tampered with or deleted.
Mr Llanto, 42, disappeared overboard off Cairns on August 30, 2012.
Mr Collado, 55, died a fortnight later after plummeting 12 storeys down an engineering shaft when the ship was moored at the Port of Newcastle.
Superintendent Kosaku Monji, whose death is not being investigated, was sent to the ship to calm down the terrified crew.
But all the crew except one flew back to their respective homes before Australian Federal Police and NSW Police officers could learn much through interviews.
Mr Monji began his own internal audit of the deaths, but it was cut short when his body was found crushed and mangled in a conveyor belt on October 6 when the ship was in Japan - outside the NSW Coroner's jurisdiction.
The three men died or disappeared within a 37-day period.
Despite the possible links, Japanese Coast Guard and Japanese Transport Safety Board investigating Mr Monji's death were not told of the other two men.
The shipping company's executive director Shigeto Yoshimura appeared before the Coroner via video link from Japan, with a court-appointed interpreter translating from the courtroom.
"I don't think there is any sort of relationship amongst these three deaths," Mr Yoshimura said.
Counsel assisting the Coroner Phillip Strickland asked if it was up to the investigating bodies to decide whether possible links were relevant, not Mr Yoshimura.
"Is it the case that you didn't want the Japanese Coast Guard or the Japanese Transport Safety Board to know about the disappearance of the chief cook and the death of the chief engineer?" Mr Strickland asked.
Mr Yoshimura conceded he did not report the other deaths "probably because I did not want to delay the operation of the ship".
The inquest, which has been running since 2014, had already heard the ship's captain, Venancio Salas, had been accused of bullying and physically assaulting the crew and illegally selling guns.
Mark Sanders, who spent 23 years in the navy and specialises in voyage data recorders, testified he believed audio recordings from the days Mr Collado and Mr Llanto died had been deliberately deleted.
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