A 36-year-old South Korean-flagged charter fishing boat caused a legal flurry after it upped-anchor near Lyttelton and headed toward international waters yesterday despite a High Court arrest warrant.

The Korean officers of Oyang 77 say they were taking their rubbish out to dump in the Pacific beyond the 12 mile (22 kilometre) territorial limit.

But it seems the Koreans had a change of heart when they realised they were heading straight toward a Royal New Zealand Navy ship.

Oyang 77 is under arrest in a civil dispute with Nelson's Talley's Fishing following an incident near the Auckland Islands, in which it hit and damaged the trawling gear of the Amaltal Explorer.

Last week the Ministry of Agriculture refused Oyang 77 a licence to fish "because of concerns about this vessel's ability to comply with New Zealand fisheries regulations".

It is a sister ship to Oyang 70, which sank off Otago two years ago killing six, and of Oyang 75, whose crew walked off in protest at claimed inhumane conditions aboard.

All are chartered by Christchurch's Southern Storm Fishing (2007) Ltd, a shell company holding the interests of Korea's Sajo Oyang Corporation.

Oyang 77 has also run aground in the Chatham Islands previously.

It is one of the foreign charter fishing vessels investigated by Fairfax Media in the past year over claims of human rights and labour abuses.

Talley's operations manager Andy Smith said they got a High Court arrest warrant over Oyang last Friday. It required the ship to remain at anchor off Christchurch's South Brighton Beach until the matter was resolved.

But at 7.30am yesterday Oyang lifted its anchor without court permission and began sailing east at nine knots (16 kilometres per hour), toward international waters.

Ship tracking website Marinetraffic.com showed it had gone around 14 kilometres on a course which brought it toward hydrographic ship HMNZS Resolution.

A Navy spokeswoman said Resolution was not tracking Oyang and was conducting a survey, or "mowing the grass", in which the ship towed sonar arrays back and forward.

They radioed the oncoming ship to stay clear of its lines, but Marinetraffic.com shows Oyang 77 executed a 180 degree turn and headed back to anchor.

Oyang's agent, Marty Logan, said they did not know why Oyang had moved and had no explanation for its behaviour.

However fishing industry sources say the Korean captain said he was going to take out rubbish to dump off Banks Peninsula in international waters. The crew did not know what was happening.

Smith said they believed Oyang was in contempt of court.

He said the issue in dispute occurred in March last year in which Oyang 77 was the give-way vessel while trawling, and allegedly failed to do so.

Their trawl door entangled with Amaltal Explorer's door and as a result its door was lost.

Southern Storm refused a claim for compensation and the issue has gone to court.

- © Fairfax NZ News