Hopkins, 53, from Greytown, New Zealand, died after being thrown from his raft on Sunday, police said.
He won Academy Awards for his work on The Lord of the Rings: The Two Towers in 2003 and King Kong in 2006.
He also worked on Blade Runner, Superman, Octopussy and Transformers.
Hopkins first worked with director Peter Jackson on his 1992 movie Braindead, and was also part of Jackson’s team for Heavenly Creatures and The Frighteners as well as the three Lord of the Rings epics.
Hopkins shared his two Oscar wins and one further nomination with US collaborator Ethan Van der Ryn.
The accident happened in the Waiohine River on New Zealand’s North Island. His two rafting companions both survived.
Police Senior Sergeant Carolyn Watson said: “Police would like to thank all those who assisted in the recovery of Mr Hopkins and the rescue of his companions, particularly the jet boat operator who came to our aid and, at considerable risk to himself, was able to rescue the female.
“All three were wearing life jackets, wetsuits and helmets at the time and it appears that Mr. Hopkins got into trouble after they were ejected from the raft in a fast flowing eddie.”
Re-Printed froM BBCnews