Thai officials are investigating the activities and nationality of a ship suspected of fishing illegally in Australian Antarctic waters.

The Kunlun is on the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) international blacklist of Illegal, Unregulated and Unreported (IUU) vessels.

It is one of six ships which is believed to engage in IUU fishing for Patagonian toothfish in the southern ocean.

Last month the Kunlun was located and boarded by Australian Maritime officials.

Australia's Immigration Minister, Peter Dutton, said its crew tried to avoid detection in Thailand by entering a port under another name and flag but Australia had already alerted south-east Asian nations to its potential arrival.

The ship was detained in Thailand yesterday after being intercepted first in the Southern Ocean by the Royal New Zealand Navy, then the Indian Ocean by Australian Customs and Border Protection staff.

Thai officials are investigating the vessel's home port and activities in the region.

Mr Dutton praised Australian Customs and Border Protection staff for their role in the detention.