Japan has found itself in hot water over its "research whaling" in the Northwest Pacific amid a possible violation of an international treaty on endangered species.

Japan drew criticism during a five-day meeting in Geneva of a standing committee on monitoring wildlife trade over its hunting of sei whales from anti-whaling countries, with Australia noting that research whaling could also be used for commercial purposes.

The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which is also known as the Washington Convention, prohibits international trade in sei whales and effectively bans the catching of them in the open sea.