Police in Greenland arrested prominent anti-whaling environmentalist Paul Watson under an international arrest warrant issued by Japan, authorities and his foundation said.

His ship had just docked in Nuuk on Sunday to refuel on its way to "intercept" Japan's new whaling factory vessel in the North Pacific, the Captain Paul Watson Foundation said.

A video posted by CPWF on social media showed officers handcuffing Watson on the bridge of the John Paul DeJoria ship, putting him inside a police van on the dockside and driving him away.