The Wanted star Max George has vowed never to attend an orca show again after tuning in to watch "heartbreaking" killer whale documentary Blackfish.

The Glad You Came hitmaker was horrified by the harrowing documentary, which chronicles the plight of a whale which made international headlines in 2010 when he killed his female trainer during a live show at SeaWorld in Orlando, Florida.

The project focuses on the dangers of keeping orcas in captivity, and George was so moved by director Gabriela Cowperthwaite's film, he immediately took to his blog on Tuesday (03Sep13) to share his views with fans.

He writes, "Watching Black Fish (sic), killer whales should not be kept in captivity. It's a disgrace. So upset and angry. I won't watch an orca show again. Heartbreaking."

Bosses at SeaWorld recently spoke out to condemn Blackfish for its portrayal of the U.S. animal theme park, insisting, "Although Blackfish is by most accounts a powerful, emotionally-moving piece of advocacy, it is also shamefully dishonest, deliberately misleading, and scientifically inaccurate."