Between 2015 and 2019, police investigated 54 officers following family violence allegations.

Police quietly started then abandoned a project to address rising reports of domestic violence in their ranks.

Meanwhile, the Women's Refuge boss says it's ridiculous only a quarter of cops found by internal investigators to have committed family violence are charged.

The existence of the Lighthouse Project has become public for the first time following inquires by Stuff.

KIRK HARGREAVES/STUFF Just one in four cops subject to upheld internal allegations of family violence are charged, inquiries by Stuff have revealed.

The project was initiated to respond to the problem of increasing "family harm" within police, according to an internal document obtained under the Official Information Act.

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That document said "a steady increase in reported family harm incidents involving police" were coming to the attention of police professional conduct staff, who investigated misconduct.

BRADEN FASTIER / STUFF Blair McKenzie talks about a generational curse of family harm before he embarks on the White Ribbon bike ride around the South Island of New Zealand.

It cited American research suggesting domestic violence was two to four times more prevalent in police families than the general population.

Do you know more? Email george.block@stuff.co.nz

The overview also mentioned the high-profile case of former Invercargill policeman Ben McLean, jailed in 2017 for at least 17 years for killing his wife and shooting her new partner.

GEORGE BLOCK/STUFF Information about the Lighthouse Project can be revealed after Stuff obtained an internal summary.

Among the actions discussed by the Lighthouse Project overview were training, counselling, support lines, welfare grants and a clear family harm policy.

Police deputy chief executive people Kaye Ryan said in a statement family harm was taken extremely seriously by police.

The Lighthouse Project was due to be piloted in Canterbury early in 2019 but was "superseded by district priorities" following the Christchurch attacks on March 15, she said.

LAWRENCE SMITH/STUFF An internal document reveals police concern at rising family violence reports involving their staff (file photo).

"That being said, this does not mean the issues initially identified by the Lighthouse Project are not being addressed.

"In fact, they have been encapsulated in a broader wellness context, which covers all aspects of staff wellness."

Between 2015 and 2019, police investigated 54 officers following family violence allegations, according to data obtained by Stuff.

RNZ Strangulation is such a strong precursor to someone eventually dying in a domestic violence incident, it was recently made a separate offence.

Allegations were upheld in 32 cases involving sworn staff.

But only eight of those 32 were charged and just three received convictions.

One officer was dismissed, six resigned during the process and nine subsequently left police.

Women's Refuge chief executive Ang Jury said domestic violence has long been a problem among police officers, as it was among military serviceman.

"It's certainly no secret.

"Police are a huge organisation ... it's not surprising they would have an issue. It is problematic when they're the people who are charged with dealing with it in the wider population."

The fact only a quarter of officers who were the subject of allegations upheld by internal investigations went to court did not impress Jury.

"That's ridiculous. Our stats are bad enough."

In response, Ryan said while internal investigations may uphold breaches of the police code of conduct, that did not necessarily mean the incidents reached the threshold for criminal proceedings.