In one of two judgements handed down in Hamburg, Germany, where the Tribunal is based, Judge Rüdiger Wolfrum said the Hoshinmaru – which was boarded and detained in June – and its catch on board should be released promptly upon the payment of a bond of 10 million roubles, or about $392,000.

The Hoshinmaru’s master and crew “shall be free to leave without any conditions,” Judge Wolfrum also said, having noted earlier that Russia and Japan disputed whether the master and crew are still being detained, along with the vessel, in the port city of Petropavlosk-Kamchatskii.

Japan took action at the Tribunal last month, arguing that Russia had breached its obligations under the UN Convention on the Law of the Sea, which states that arrested vessels and their crews should be released promptly once a bond or reasonable security has been posted.

The judges upheld that argument and found that the Tribunal did have jurisdiction over the case.

But in the case of a second vessel, the Tomimaru, whose crew was released after it was detained in October last year, the Tribunal ruled that Japan’s application was “too vague and general” to be admissible and that a Russian court had already confiscated the vessel in question.

Russia said it had detained the two vessels because they had violated the country’s national fisheries laws within its exclusive economic zone.