"It's time for change and that change is now. We must use up to date research in relation to male victims of sexual trauma," Clearwater, who 30 years ago opened up about being raped as a 12-year-old, said.

"We have a chance here to get it right... In the case that the perpetrator is a woman, the survivor may be mocked or feel ashamed that a woman overpowered him."

He said it's not about "minimising the situation women and girls are enduring right now", and said there is often "hostility" when the topic is brought up because "there is the assumption that the speaker is choosing sides".

He added, "This isn't a game. There are no sides... I am here to ensure all victims, regardless of gender, get the proper services and support they deserve through our justice system."

Clearwater said he's concerned that male sexual abuse survivors are still not being taken seriously in New Zealand and that they are often overlooked when statistics show women are more often victims than men.

Clearwater pointed to Ministry of Justice data showing women - 2.9 percent - were more likely than men - 1.1 percent - to have experienced a sexual offence in 2013.

The ministry's most recent data from 2018 shows 3.08 percent of females have experienced sexual victimisation compared to 1.32 percent of males.

The lifetime experience of sexual assault from the 2018 data is 34.01 percent of females and 12.19 percent of males.

Clearwater said comparisons made between the frequency of female and male sexual assault should not matter and that they should be treated the same.

"Why do we have to compare? This is not a competition. Regardless of gender and numbers, these human beings are all victims of sexual trauma... All victims regardless of gender, deserve fairness through the justice system."

The Sexual Violence Legislation Bill aims to reduce the re-traumatisation victims of sexual violence may experience when they attend court and give evidence.

Clearwater said he supports the legislation, but wants an assurance that "all workers in the justice system have specific training for male sexual trauma, especially historical cases".

He added, "We know it takes up to 33 years for some male survivors to come forward".

Clearwater also mentioned the Royal Commission of Inquiry into Abuse in Care which is looking into what happened to people while in state care, or in the care of faith-based institutions, between 1950 and 1999.

"We are going to have a lot of men come forward and we need the justice system to know how to get through that," Clearwater said.

He pointed to the 2004 report by the John Jay College of Criminal Justice, commissioned by the US Conference of Catholic Bishops, which found 81 percent of victims of clergy abuse are male.

"We struggle, for an unknown reason, with research here in New Zealand in relation to male victims of sexual trauma and female sex offenders - we rely heavily on overseas research... I hope one day we will get it right here in our country," Clearwater said.

"I want to put the male survivor voice to this important Bill."

The Government announced $320 million over four years in Budget 2019 to fight family and sexual violence, $32.8 million of which is to improve the justice system's response to sexual violence victims.

The Government is already progressing with some recommendations made by the Law Commission, including tighter rules around evidence about a complainant's sexual history.