Four men and a shipping company charged in connection with the August 2009 sinking of the Tongan ferry Princess Ashika, in which 74 people drowned, have been found guilty on all charges.

The jury returned their verdicts to the Nuku'alofa Supreme Court at 10.20am this morning, the Matangi Tonga website reported.

The jury retired on Wednesday afternoon.

The four found guilty were John Jonesse, the New Zealander who was managing director of the Shipping Corporation of Polynesia (SCP), Ashika 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 other 72 passengers and crew who died - including all of the women and children on board - included a New Zealand citizen, and Niuean policewoman Sisiliah Rachelmana Puleheloto, 24.

The Supreme Court trial began on February 11.

The four men have been remanded in custody for sentencing on April 4.

In Tonga manslaughter by negligence can attract penalties of imprisonment not exceeding 10 years.

Royal Commission of Inquiry

A Royal Commission of Inquiry into the sinking - held before the trial - said last year that it was "alarming" the Shipping Corporation of Polynesia recommended the ferry's purchase "without any proper due diligence, surveys, inspections, valuations, documentation or proper inquiry having been completed".

The seven-member jury retired at 3.11pm on Wednesday, after Justice Robert Shuster spent five hours summing up the case at the Supreme Court in Nuku'alofa. It resumed deliberations today and will continue tomorrow, Radio New Zealand International reported.

Justice Shuster canvassed the Crown and defence cases as well as the specific case against each of the five defendants, and pointed to evidence by witnesses, including the crew's account of the difficulties they had bailing water and reporting problems to senior officers on the night the ferry sank, Matangi Tonga website reported.

The judge also reminded them of surveys which showed the ship's deteriorating condition and that the owners were aware of the state of the ship. He said an essential question to be answered was whether the MV Princess Ashika was seaworthy or not to sail.

"Did the Shipping Corporation of Polynesia Ltd and John Jonesse, as managing director, know of the deficiencies on the vessel? And did Jonesse, as the controlling mind of SCP, have prior knowledge of those deficiencies, is again a matter for you to consider," he asked the jurors.

Noting the exhibits in court included a list of the ship's deficiencies, Justice Shuster urged jurors to consider whether the defence could rely on an argument that the company sent the vessel to sea because it had valid certificates and before the deficiencies were fixed.

"The Crown submitted that the defence hid behind this piece of paper," Justice Shuster said.

He also asked whether the death was caused by the defendants being grossly negligent.

"Did Jonesse forge David Shaw's signature or not and did Jonesse use the document to deceive others? Was Jonesse aware he used a forged document in order to deceive others?" Justice Shuster said.

- NZPA, NZ Herald staff