Chief executive Deb Tozer told the Mercury Care South had always had a "positive experience" with the mandatory checking system, believing it worked well in screening carers.

Potential carers were subject to a strict screening process, including working-with-children checks, criminal-record checks and child-protection checks, plus interviews with the carer and others who lived in the home.

While Care South was aware other agencies had said the system was not "fool-proof", Ms Tozer said her organisation's experience had generally been positive.

Her comments came after Fairfax Media revealed a backlog of hundreds of allegations waiting to be investigated by the Department of Family and Community Services, which manages complaints about foster carers.

Ms Tozer said Care South's own monitoring system had worked well in balancing the needs of carers and children.

"Our team does all the case management and home visits so we work much more closely with foster carers," she said.

Though teams sometimes met some resistance from carers about the regular welfare checks, Ms Tozer said most foster parents, particularly relatively new carers, welcomed the visits.

"A lot of them welcome the support," she said.

"They want to be able to talk through things that are happening and get that guidance and support.

"Our primary concern is the safety of children and making sure our carers provide the best quality care."

Ms Tozer said Care South had a system in place to respond to any complaints made by children, including reporting the incident to the relevant authorities and investigating any allegations.

She encouraged kids to have an open relationship with their caseworkers and feel confident to speak out.

"Children can raise any concerns they have," she said.

"Sometimes they find it hard and we've had children speak out because they didn't know their rights. Our caseworkers have a really good understanding and we really encourage them to talk with the children; we want them to have their own voice and be able to speak up.

"It's all about finding the right placement and matching children with the right carers - sometimes children will say their placement just didn't feel right - it's not that there was anything wrong, it just wasn't quite right, so that's the challenge for us."