The deliberate discharge of nuclear-contaminated water into the sea is unprecedented and violates the International Convention on the Law of the Sea, said a group of environmentalists in Japan.

"The deliberate discharge of contaminated water from nuclear accident into seas, oceans or rivers is unprecedented. Many scholars around the world have pointed out that even treated nuclear-contaminated water must not be discharged into the sea. The forced discharge violates the International Convention on the Law of the Sea," said Hisataka Yamazaki, head of No Nukes Plaza.