Social Development Minister Anne Tolley has stopped a risk modelling study aimed at predicting child abuse.

The study would have seen children monitored but any risks they faced wouldn't have been acted on to see if they would be abused.

Tolley wrote notes on official documents saying she did not want the study happening on her watch and that children are not lab rats.

"I was shocked that anybody would be proposing that, and I wanted to make it clear that it was not going to happen in any way, shape, or form," she said.

She said the only way she could explain it was that officials were quite passionate about what they were doing and they just got carried away.

"They knew they had to go through a process around ethics, but you would have thought someone would have said: "hang on a minute, how sensible is this? how reasonable is this?" Did anyone do this? I don't believe anyone could have."