Ric O'Barry (Photo/Wechat)

U.S. animal right activist Ric O'Barry who featured in "The Cove", a documentary about dolphin slaughter in a Japanese town which won the best Oscar documentary award, has been detained in Tokyo by immigration authorities after being denied entry to the country on Monday.

According to his lawyer, O'Barry arrived at Tokyo's Narita International Airport for investigating the current dolphin slaughter situation in Japan and travel around Kyoto. He planned to go back in early Feburuary. However, he was denied entry to Japan on a tourist visa, detained by immigration officials at the airport and interrogated repeatedly.

76-year-old O'Barry is a famous dolphin activist who appeared in "The Cove", the Oscar-winning documentary which drew worldwide attention to the annual dolphin hunt in the small Japanese town of Taiji. However, the movie led to the protest of furious local fishermen, as they consider hunting and killing dolphin is part of the "traditional culture."

The crew of "The Cove". (Photo/Wechat)

It is not the first time O'Barry has been detained by Japanese authorities.

Last September he was arrested near Taiji on the eve of the start of the controversial six-month dolphin hunt, for allegedly failing to carry his passport after being stopped by police. He was released the following night.

O'Barry's lawyer argues that O'Barry always visits Japan in this time of the year with the same purpose. It is unreasonable that he was denied entry this time.

The last social networking post by O'Barry himself is an Instagram photo with the comment: "Here we go again...", showing an immigration sign apparently at a Japanese airport, dated Sunday.

O'Barry has raised an objection for being denied entry according to Kyodo News Service's report. Tokyo Regional Immigration Bureau refused to respond to it since it was considered as an "individual case" which needed to be processed based on Right to Privacy.