The world's longest-running birth cohort data collection, the Dunedin Study, found women were just as likely to be domestic violence perpetrators as men.

The findings of an in-depth domestic violence study, which showed violent conduct almost evenly split between the genders, are potentially cause for concern, a senior police officer says.

South Canterbury Family Violence Co-ordinator Senior Constable Steve Wills was reacting to the findings of an analysis forming part of the world-renowned Dunedin Study, which has focused closely on the lives of more than 1000 people born in Dunedin in the year ending March 1973.

"It presents a challenging picture. If the findings were a true reflection of our community, we should be concerned," he said.

Wills said recent 'mainstream' studies on the subject had shown about 80 per cent of the perpetrators of domestic violence were men.

However, in their paper "A couples analysis of partner abuse with implications for abuse-prevention policy", authors Terrie Moffitt, Richard Robins and Avshalom Caspi found a more even split between the genders when it came to violence in the home.

They found that 40 per cent of male couple members in the study had perpetrated at least one of a list of 13 physically abusive acts, ranging from slapping and kicking to forcing sex and use of a weapon, while 50 per cent of women had.

The data did not fit the male-dominance model, which attributes aggression mostly to men, the researchers concluded.

"[It] would suggest the need for policy that encourages development and evaluation of programmes to reduce physical abuse by women," the authors stated.

Wills said because the Dunedin Study participants had no concerns over privacy and their confidentiality was guaranteed, he believed the information they shared was likely to be less confused than that provided by respondents in mainstream studies. They also did not have to be concerned with outcomes.

"Other victims' (non-Dunedin Study) evidence resulted in interventions from agencies across the board," he said.

Wills has worked in anti-violence since 1999 and said he had seen female victims calling for assistance earlier than male victims in violent situations.

"Men will not ask for assistance because they feel shame being beaten or dominated. It's complex."

Anti-violence programmes for men in South Canterbury were meeting demand but there was a waiting list for education and support programmes around managing anger for women, he said.

He said traditionally women were seen as nurturers and supporters but there had been a shift away from those roles as women took up leadership positions and became primary money earners.

South Canterbury Women's Refuge manager Dawn Rangi-Smith had not seen the research but wanted to know if it included the context of the abuse and whether women who committed violent acts were reacting to abuse from men.

Though the refuge was gender-based, Rangi-Smith said it was important to look at violence as a whole and not separate it.