Children's Commissioner Andrew Beecroft is cautiously supporting a police proposal to pay people to dob in child abusers.
The plan has been revealed as another shocking and horrendous story of neglect has come to light, after a landlord found faeces and maggots in a Nelson house where two children under nine had been living.
Other child abuse cases have ended fatally and Detective Superintendent Tim Anderson says people had known abuse was going on.
"When we look and debrief cases like Nia Glassie, Kahui twins, we know that within the family environment there are people there that know the offending or abuse is taking place," he said.
Mr Beecroft supports the idea of paying informants.
"With proper safeguards to those serious situations who could be against it if it saves the life of a child?" he said.
But the former Youth Court judge concedes people could abuse the system.
It wouldn't be taken at face value- Detective Superintendent Tim Anderson
"Complaints could be made for money. They could be trumped up complaints, they could be half truths used to further the interests of a party. So it would have to be for serious alleged instances where no other information is available," Mr Beecroft said.
Police wouldn't say how much or when informants would be paid.
"We'd take the information and then investigate thoroughly. It wouldn't be taken at face value," Mr Anderson said.
In the Nelson case, the mess was discovered by landlord Sinead Ogilvie after her tenants moved out owing 10 weeks rent.
Ms Ogilvie says pleas to Child Youth and Family to help the children fell on deaf ears, she penned an open letter to CYF.
"How many times will we ignore the warning signs of neglect of Kiwi kids in New Zealand homes?" the letter asked.
She outlined shocking living conditions with carpet soaked in "urine, human and dog faeces in every room" as well as rotten food, cigarette butts and methamphetamine and cannabis utensils.
CYF is now investigating and has apologised, admitting they "have not done a good enough job".
The government agency says staff have visited the children and will be monitoring their situation closely to ensure their safety.