1.09pm BST

The ruling in the Hague will not stop Japan from developing another scientific whaling programme to replace the now outlawed JARPA II. But it will have to prove the research cannot be done without killing whales.

The court did not find that lethal research methods were unscientific. Judge Peter Tomka said in summing up: "The use of lethal samples per se is not unreasonable in achieving the objectives of JARPA II."

Sarah Gregerson, from ClientEarth said: "The court did find that JARPA II could be broadly categorised as scientific research. But when you look at whether it is for the purposes of science, that is where it falls."

Japan's conduct, rather than the programme itself, lead the court to infer that their primary motivation was not scientific and therefore the country was in breach of the International Convention for the Regulation of Whaling (ICRW).

The court said there was no research justification for the high kill targets set for Japan's whalers. Other aspects of the programme that cast doubt on Japan's intentions were:

The open-ended time frame of the programme

Limited scientific output

A lack of cooperation and collaboration between JARPA II research and other international research on whales.

Gregerson said the court ruling left the door open for Japan to create a new Southern Ocean whaling programme for the purposes of scientific research. The ICRW allows contracting nations to develop their own research programmes.

But any new programme will need to prove the necessity of its lethal methods. A key aspect of the judgement will be the court's finding that Japan's programme did not adequately consider non-lethal alternatives. Gregerson said this will guide the scientific committee of the International Whaling Commission on how whaling research should be conducted. Particularly, that any programme must prioritise non-lethal methods.