They are described as stories in the skin waiting to be told: stories about Maori, whakapapa and genealogy.

Waikato University psychology lecturer Ngahuia Te Awekotuku is researching the stories and traditions of moko - facial and body tattooing.

Professor Te Awekotuku has been researching moko for "years", and has seen changes in the art and its exploitation.

"It's a physical art form and very personal. We want to protect that information as part of this research. But it is a concern that moko is being exploited.

"Many European designers are recognising moko as something of beauty and elegance. But they use it to enhance and sell their products. People are disturbed by the use of moko as a fashion accessory."

Professor Te Awekotuku said moko was also gaining a higher profile, with people such as Robbie Williams and Ben Harper getting their skin tattooed.

"It's an evolving field and an exciting one, but their moko is slightly different. We call it kirituhi [inscribed skin], whereas traditionally moko is something that people earn and have magical connections with their history."

Waikato University psychology lecturer and researcher Linda Waimarie Nikora said moko was becoming a new phenomenon and people were having to find new meanings for it.

"Moko is staging a revival, and it's a contemporary controversy. ... But people are realising that it's part of New Zealand and its heritage."