The Maori radical who smashed the America's Cup with a sledge-hammer has turned his skills to film-making and is working on a documentary about Prime Minister John Key.

Penehamine Netana-Patuawa, formerly known as Benjamin Peri Nathan, says he wants to define himself as a film-maker and has put his criminal past – bank robbery and drug-dealing – behind him.

"My sole focus nowadays is making films and documentaries," Netana-Patuawa, who was sentenced to two years and 10 months' jail for wilful damage as a result of his 1996 attack on the "Auld Mug", says on his website.

The Sunday Star-Times asked Netana-Patuawa for an interview about his planned documentary on the prime minister but he said he was extremely wary of non-Maori media because of their focus on his past. He said he would agree to be interviewed only if the paper signed a one-page contract outlining the purpose of the story and the questions it wanted answered and promised not to focus on the America's Cup attack.

On his website, www.johnkeydoco.co.nz, Netana-Patuawa claims he seeks to "reveal the truth" with his documentary although he admits his main motivation is that he is deeply angered by the policies of Key's National-led government which he blames for the injustices he sees.

"We live in a land of abundance, yet we have many people, particularly children, suffering. John Key is responsible for that and, as such, I intend to hold him to account. But, my doco will not seek to go on some type of vindictive `witch-hunt'.

"Rather, I will be only seeking to reveal the truth, backed up with hard facts and evidence," Netana-Patuawa says.

He goes on to say he wants to express his creativity as a film-maker by creating a powerful, yet artistic, documentary, told in his own unique way.

"I know making the doco from start to finish is going to be a daunting task, but I am up for it."

Producing a documentary is an expensive business and Netana-Patuawa needs money to get his project off the ground so he is seeking sponsorship and donations, or koha.

"If just 2000 people committed to $1 a week over a one-year period, that would cover the costs of the entire documentary," he says on his website, adding that an accounting firm has been employed to ensure all money received is spent on the doco.

He is also looking for people to help make the documentary but says he has no interest in hearing from National supporters: "A background check will be taken to make certain you are not a National supporter, as I do not want any `National spies' relaying information back to the party pertaining to the documentary. I know this may sound a bit `paranoid' but better to be safe than sorry."

The prime minister did not want to comment on the plan.

Netana-Patuawa began film-making in 2009 and has two short films to his credit, Te Whakapouri ... The Darkening, about a Maori warrior prophet who undergoes a series of bizarre tests in his faith, and A Dignified Life, about a teenager dying of leukaemia.

- © Fairfax NZ News