According to a senior member of the association, who received an envelope containing a Japanese-dubbed DVD of "The Cove," which won an Oscar in 2010, the package's sender was "Umi o kangaeru gurupu" (a group that thinks about the ocean).

Along with the DVD, the envelope contained a message urging recipients to watch it once to judge what the movie wants to convey, he said.

He said the DVDs have apparently been sent to households not involved in fishing, as well as to fishermen's households.

"It's creepy. I don't plan to watch it," he said.

The film, directed by Louie Psihoyos, depicts the dolphin hunt in Taiji, partly through graphic images taken by hidden cameras. It was released in Japan last July but has not been shown in the town.