Photo: RNZI/Johnny Blades

The Supreme Court in Papua New Guinea has upheld the right of refugees detained on Manus Island to claim damages for unlawful detention.

The Court has today dismissed an application made by the State last December, to throw out the refugees' claim.

More than a thousand men have been detained on Manus since 2013 under a memorandum of understanding with Australia.

In April 2016, their detention was ruled unconstitutional in PNG, and in November that year they commenced court proceedings to seek compensation.

Refugee advocate Ian Rintoul says today's finding opens the way for major damages to be paid to refugees by both the PNG and Australian governments.

Mr Rintoul says refugees not part of a $US50 million compensation deal struck with the Australian government in Septemeber will be eligible.

He says summary judgement and consequential orders are expected to follow in a February.