Revelations of the piracy of New Zealand film Boy illustrates the growing threat of online copyright theft to the New Zealand film industry.

Boy, Taika Waititi's heartfelt coming-of-age tale set in the East Coast, was made available on a peer-to-peer filesharing site earlier this month - potentially hurting its upcoming DVD and Australian release.

"It's a sad day for the New Zealand film industry when something like this happens," said New Zealand Film Commission CEO Graeme Mason.

"Whilst Boy has already been a tremendous success at the New Zealand box office, it is yet to be released overseas. There's no telling how much the film's true international potential has been hurt by piracy."

The film is set for an Australian general release in August - with early indications of a repeat of the film's New Zealand success after screening to sell out audiences at the Sydney Film Festival and being voted the Best Fiction Feature Film by the Festival's State theatre audience. This is the first time in 20 years a New Zealand film has won the award.

Boy is financed by the NZ Film Fund, NZ Film Commission, Unison Films, NZ On Air, Maori Television Service and Te Mangai Paho.

Mason adds, "Ultimately piracy hurts not only those directly involved in making the film, but those who work in the wider industry. Strong returns on movies such as Boy enable the NZFC to invest more money into developing more New Zealand stories that resonate not just with Kiwis, but with audiences around the world. That's a good thing for the industry and for New Zealand as a whole."