A Florida-based man, who had sex with Dolly the dolphin in a year-long "relationship" in 1971, has revealed that it only happened because she "seduced" him.

In a new 15 minute documentary, the 63-year-old Malcolm Brenner, from Punta Garda, said that he started rubbing her along her back, working her way to her flukes, her tail and as he was rubbing her and moving her hand towards her tail, Dolly was slowly rolling around her long axis, the Mirror reported.

In the film, 'Dolphin Lover,' an animation of what it's like to have sex with a dolphin is played to viewers to help them with their imaginations.

Brenner, who was given free access to the dolphins at the former theme park in Sarasota Florida, where he lived, and became friends with her by going swimming with her, said in an interview that there's something quite transcendental about making love with a dolphin as she was very special.

Brenner, who was a photographer at that time, mentioned that she announced her intentions to him by positioning herself so he was rubbing against her, adding at first he discouraged her as he wasn't interested, but after some time he thought "if this was a woman would I come up with these rationalisations and excuses?"

He added that it was when the park was closing that they successfully eluded the male dolphin so we could spend some time alone.

He said that he called it a relationship because that's what it was and when she died it made him feel terrible and so he fell into a depression which lasted five years.

Dolly was moved away when the park closed nine months after they had first met and Brenner says that he believes her death, a short time later, was a case of suicide and that she voluntarily stopped breathing.