The star of Academy Award-winning 2009 documentary The Cove, about a dolphin hunt in the small Japanese village of Taiji, was detained by immigration officials at Narita International Airport in Tokyo last month (Jan16) as he attempted to enter the country on a tourist visa.

His lawyer, Takashi Takano, appealed the activist's detention, and on Friday (05Feb16), O'Barry was sent back to the U.S.

O'Barry, who has been accused of having links to anti-whaling organisation Sea Shepherd, was previously arrested in Japan in August (15) while protesting against a dolphin hunt.

However, the 76-year-old maintains he was travelling to Japan in January to enjoy dolphin watching.

"It breaks my heart to be deported," he told The Associated Press. "I never violated Japanese law. I never lied to Japanese authorities."

Discussing his treatment by local authorities, he added, "This is a slap in the face to the freedom of speech. But this has not shaken my love for Japan."