Survivors' support group One in Four has said Tusla's (the state's Child and Family Agency) investigations into entirely credible allegations of child sexual abuse throughout the State regularly conclude with no action being taken.
Executive Director Maeve Lewis said she believes this results in many children being unnecessarily exposed to the risk of sexual harm.
Referring to the current fostering controversy in the southeast, she predicted there would be more revelations of sexual abuse of vulnerable children because of the State's failure to act.
Ms Lewis's comments follow yesterday's report by the Health Information and Quality Authority into the State's Child Protection Services in Tusla's Dublin southeast/Wicklow area.
Ms Lewis said the report confirms the experience of its clients - adult survivors of child sexual abuse - in engaging with the services.
She welcomed the watchdog's finding of very good practice in relation to allegations of current sexual abuse of children.
She added, however, that the report highlights the failures of the service to adequately investigate allegations against people who are still alive which have been made by adults in relation to sexual abuse in the past.
HIQA's report concluded that this may pose a significant risk to children. She said the support group notified all these concerns to Tusla.
"Just because the sexual abuse took place ten, 20 or even 30 years ago does not mean that the sex offender has stopped abusing children" she said.
"Through our sex-offender intervention programme we have learned that abusers tend to continue abusing until they are detected.
"The father who abused his children may now be abusing his grandchildren, the teacher who abused a pupil may be abusing the next generation of schoolchildren" she said.
She said One in Four's experience of making notifications to Tusla is reflected in the HIQA Report.
"Cases languish on waiting lists for long periods. Assessments of retrospective allegations are complex and we are very dissatisfied at the quality of many assessments. Staff interviewed by HIQA acknowledge the lack of training they receive in this regard.
"Investigations into allegations that we believe to be entirely credible regularly are concluded with no action being taken. I believe this means that there are many children out there who are unnecessarily exposed to the risk of sexual harm" she said.
Ms Lewis described as "very encouraging" HIQA's ushering in of a new level of transparency and monitoring to child protection services.
She said the failures identified in the report are partly due to too few social workers being in place and a lack of adequate training for staff.
"However, HIQA also highlights how retrospective allegations are treated less seriously than those of current abuse.
"Unless increased funding is made available to Tusla to invest in child protection services, it is likely that these failures will continue.
"In the past weeks the people of this country have been horrified, yet again, at failures in child protection" in the southeast.
"A this report shows, we can expect future revelations of the sexual abuse of vulnerable children because we failed to act," Ms Lewis added.