Survivors of child sexual abuse often fear engaging with the criminal justice system because of "adversarial" trial practices, according to a support group for victims.
Maeve Lewis of One in Four said victims were "regularly humiliated, demeaned, undermined and retraumised" during trials.
"The criminal court is adversarial. It is not an an ideal place to tease out the complexities of sexual abuse," she told Newstalk.
Ms Lewis was speaking ahead of the launch of One in Four's annual report for 2015, which showed that almost 40% of the charity’s clients had been sexually abused by a relative.
The others were targeted in their communities (11%), in the Catholic church (22%) and by strangers (15%). Some 11% were sexually abused by a number of people.
Fewer than 15% of One in Four's clients decide to make a complaint to the gardaí, Ms Lewis said.
She explained that victims who are abused by family members can be "often very ambivalent about how they feel about the abuse.
"They hate that the abuse has happened but may still love their father or brother or uncle."
Gardaí are generally professional and sensitive in dealing with abuse allegations but investigations are sometimes not carried out in an appropriate manner, she added.
According to its annual report, One in Four provided 2,563 therapy hours last year to 116 adult survivors and 40 families.
A total of 45% of its clients were men – a figure which challenges the idea that boys are not sexually abused, the charity has pointed out.
The others were abused in their communities 11%, Catholic Church 22% & strangers 15%. 11% were sexually abused by multiple abusers. #1in4
— One in Four (@oneinfourirish) October 12, 2016
The organisation also worked with 38 sex offenders and 19 wives and partners in 2015 as part of its group treatment programme.
Ms Lewis said: "Most of these offenders will never face a criminal trial because their victims do not wish to make a garda statement.
"But we have also learned that the wives and partners of the offenders play a vital role in child protection.
"Many of these women are highly dependent on their partners, and often blame the child for what has happened.
"One woman told us that her 11-year-old daughter was 'a slut who had stolen her husband from her'.
"Through our work with the wives, they come to understand the part they have played in the family dynamics that supported the abusive behaviour.
"They can then work with Tusla to keep their children safe."
Child sexual abuse has a devastating impact on men and women from all walks of life, she said.
"Many experience chronic post-traumatic stress. Some struggle with relationships and parenting. Many experience suicidal thoughts.
"Sadly, we cannot respond immediately to the people who contact us and some are waiting up to six months for an appointment.
"We know that four people have taken their own lives while on our waiting list in the past four years. This is an absolutely preventable tragedy."
Ms Lewis said the Criminal Justice (Sexual Offences) Bill 2015 currently proceeding through the Oireachtas will bring in important changes that may improve victims' experiences of the criminal justice system.
She also welcomed the EU Victims’ Directive of November 2015, which introduced specialist training for judges and legal professionals.
But she stressed that all cases must be properly dealt with by child protection services, however challenging this may be for social workers.
One in Four passed on 49 sex abuse allegations to Tusla child protection services last year but most were deemed to be "unfounded".
"While we appreciate the difficulty social workers face in assessing retrospective allegations, this does imply that many credible allegations will not be pursued, and children will be at risk," Ms Lewis said.