Conservation group Sea Shepherd has come to the aid of the crew of a poaching vessel that sank off the coast of West Africa.
The Sea Shepherd ships Bob Barker and Sam Simon were rescuing the crew of 40 who were able to disembark from the ship Thunder before it sank.
Sea Shepherd has been pursuing the ship for four months.
Captain of the Bob Barker, Peter Hammarstedt, said: "When my Chief Engineer boarded the Thunder in the hours leading up to the sinking, he was able to confirm that there were clear signs that the vessel was intentionally scuttled.
"Usually when a vessel is sinking, the captain will close all hatches so as to maintain buoyancy. However, on the Thunder, the reverse was done - doors and hatches were tied open and the fishhold was opened. It is an incredibly suspicious situation, to say the least."
Mr Hammarstedt told Radio New Zealand this morning that his ship had been tracking the Thunder for 110 days since finding it fishing illegally in Antarctic waters.
Bob Barker was about half a mile away from the ship when it put out a distress call, and the crew began getting into life rafts.
The captain of the Thunder claimed it was struck by a cargo ship in the early hours of the morning.
He said when the Bob Barker arrived on the scene the Indonesian crew members appeared to have been taken by surprise by the sinking, but the officers on board had suitcases packed.
Mr Hammarstedt said he had no doubt the ship had been scuttled.
"We've been reporting to interpol and the Ministry of Primary Industries in New Zealand every day. They were at the end of their fuel and I'm confident that the captain of the Thunder thought he'd rather see the physical evidence that was on that vessel go down with that vessel."
The crew of the Thunder had been segregated from the Sam Simon's own 20 crew, because they had been violent towards the Sea Shepherd crews in the past.
He told Radio New Zealand the crew would be taken to the nearest port in the Gulf of Guinea and handed over to authorities.
No one was reported injured, according to Sea Shepherd.
The crew of the Thunder have been supplied with food and water, and will now be received by the Sam Simon.
Captain of the Sam Simon, Sid Chakravarty, said, "With the safety of my own crew also in mind, we will now take every precaution to ensure that the crew of the Thunder is retrieved from the lifeboats safely."
The Thunder is one of six vessels called the "bandit 6" by Sea Shepherd that are known to engage in illegal, unregulated, unreported fishing of vulnerable toothfish in the Southern Ocean.