Mediators say they could cut the number of suicides and murders caused by marriage breakups if the Government funded mediation in child custody disputes.

Arbitrators and Mediators Institute director Deborah Hart said a mediation scheme was recommended by the Law Commission in 2003, piloted at four courts in 2005-06 and passed into law last year - but it had still not been implemented because of the cost.

Principal Family Court Judge Peter Boshier said yesterday that 18 people involved in Family Court processes had committed suicide and four others had been killed in the 13 months to last June.

Ms Hart said some of those people might be alive today if the mediation scheme had been implemented.

"This month there was an article in the NZ Law Journal linking a case where a father involved in a messy custody dispute killed his wife," she said. "Mediators, lawyers and counsellors all know that a collaborative early intervention could have helped."

The article, by Gaye Greenwood, a mediator who took part in the pilot at the North Shore court, cited the death two months ago of Helen Meads, wife of Matamata racehorse owner Greg Meads.

She quoted news reports that the death followed an argument over custody of their 8-year-old daughter Samantha.

"We wonder what would have been possible if Helen and Greg had sought counselling or mediation to better understand their inter-parental conflict and renegotiate their parenting relationship," Ms Greenwood wrote.

Free relationship counselling and judge-led mediation are already available through the Family Court, but funding the legal provision for mediation over child custody issues through lay mediators is still in the Budget queue.

Justice Minister Simon Power said yesterday: "The funding of new services needs to be carefully considered against all government priorities, particularly given the current economic climate. But full consideration will be given to this course of action."

A Justice Ministry evaluation of the 2005-06 pilot found that mediation in custody disputes took an average of less than four hours and cost an average of $777.

Most (59 per cent) of the mediations reached agreement on all matters and 30 per cent on some matters.

Ms Hart said the cost, even if the scheme extended to most of the 67,000 new applications to the Family Court each year, would be "tiny compared to the cost of taking cases through the court system, not to mention psychic costs".

"Everyone who has anything to do with the Family Court system notes, as Judge Boshier has, that the stress caused to the parties in the court is enormous," she said.

Mr Power said he would also consider the judge's proposals to train court staff to refer distressed people to mental health services, and to create a new agency to refer and monitor people in counselling for domestic violence.

"Judge Boshier has added some very constructive suggestions to the debate", Mr Power said, "but they will have to be considered against all priorities, and in particular as part of Budget 2010."