Families of the passengers whose lives were lost in Tonga's Princess Ashika ferry tragedy say they are happy the men responsible for sending the unseaworthy ferry to sea have been found guilty.

A jury in the Nuku'alofa Supreme Court found four men, including New Zealander John Jonesse, and a shipping company, guilty.

Besides Jonesse, who was managing director of the Shipping Corporation of Polynesia, the other men convicted were the ferry's captain, Viliami Makahokovalu Tuputupu, first mate Semisi Pomale and a former director of the Ministry of Transport, Viliami Tu'ipulotu.

The corporation was also charged, and collectively the defendants faced 30 counts, including one charge each of manslaughter by negligence in relation to the death of Vaefetu'u Mahe, 22, the only Tongan whose body was recovered after the sinking.

The only other body recovered was that of Daniel McMillan, a Briton who had been living in New Zealand.

The men face up to a decade in jail in Tonga, where manslaughter by negligence can attract penalties of imprisonment not exceeding 10 years.

The family of Niuean policewoman Sisiliah Rachelmana Puleheloto, a New Zealand citizen aged 24, say they are happy with the jury's decision. Sister-in-law Sonia Taifinofu-Puleheloto said: "We are very happy. But it's not enough. They should go to jail for life."

She said that if it weren't for the men's bad decisions, all the grieving families would still have their loved ones with them.

Mrs Taifinofu-Puleheloto said the family still struggled to accept the fact that "Sisi" was gone, particularly because she could not be given a proper burial.

"We don't even have a death certificate for her yet. At the moment our memorial for her is at home. She has her own corner in the living room, with her photo, her police cap and her uniform."

Meanwhile, the New Zealand family of three of the victims have moved to Tonga to be closer to their loved ones killed in the tragedy.

Ponifasio Mailangi lost three family members - his aunt 'Atelete and cousins Tapuaki and Paula Mailangi, who had Down syndrome.

Mr Mailangi said 'Atelete Mailangi's eldest daughter, Elisapeta 'Ofa, who lived in Christchurch, had moved her family to Tonga after the sinking.

"They wanted to be closer to them. It was a very hard time," he said.

Speaking about yesterday's verdict, Mr Mailangi said the family were no longer interested in what happened to the people involved in the lead-up to the sinking.

"We did feel for the captain, because of the pressures in Tonga to get the job done.

"But now, we just want to get on with our lives. We want to move on and not think about them."

Justice Robert Shuster said in his summing-up this week that it had been "a difficult and emotive case".

All four men have been remanded in custody for sentencing on Monday.

additional reporting: NZPA, AFP