MPs have been told that people who want to work with children should be vetted and registered using a system such as the Blue Card registrations used in the Australian state of Queensland.
The Social Services Select Committee is hearing submissions on legislation that puts in place changes proposed in the White Paper for Vulnerable Children.
The Big Buddy Mentoring Trust's chief executive, Richard Aston, said on Thursday that one of the most important measures to curb that abuse is to vet people who have contact with children.
He told the committee the system is not cheap, but is well worth the cost.
"For me, I'm sorry, I take a very high moral ground with this. It's not acceptable to say cost is an issue. It's human lives at stake, and children's lives. For God's sake, we're talking about our kids."
Mr Aston said what is needed is a national register of children's workers - like the Blue Card system.