The transfer by Russia of the seized sailors to Ukraine will mean that Russia has actually complied with part of the decision of the International Tribunal for the Law of the Sea, but it still does not formally recognize its jurisdiction, Nikolai Polozov, the head of the legal team for the POW sailors, has said.

"Russia will send information to the International Tribunal for the Law of the Sea that the sailors have been released. But the tribunal does not care whether this will be done in pursuance of its decision or for some other reason," he said.

"The fact of release is important for the tribunal, and the reason given by Moscow will be different," he said.

Polozov said he found it difficult to predict the possibility of Russia's returning the three Ukrainian Naval Forces vessels it seized, saying negotiations about this would take place in the future.

Polozov said in the future, with regard to the POW sailors, there could be a decision on conviction in absentia, or they may be acquitted.

"They will not serve their sentences in Ukraine. Here they are heroes," the lawyer said.