The head of the government's justice reform panel, Chester Borrows, is questioning claims from the National Party that serious crime is on the rise.
Leader Simon Bridges told Morning Report yesterday there had been a 25 percent rise in "serious harm" crimes before the courts - such as rape, sexual assault, murder and manslaughter - since the 2017 election.
He said the figures came from district courts via written questions to Justice Minister Andrew Little, and that the increase was partly due to a "soft on crime" approach by the government.
However, government and police figures show a 2.7 percent drop - about 7000 - in the number of victims of crime reported for the year to January. The statistics do show a 4.8 percent increase in total number of serious assaults.
The crime rate in New Zealand has also dropped steadily since 1992.
Mr Borrows, a former National MP, is the chair of the government's Criminal Justice Reform Panel.
He told Morning Report the data Mr Bridges was using "did not really tell the whole story".
"The point is the law hasn't changed," he said.
"People being released on bail, people being put before the court are all being dealt with by the same law that's been in for some time, including the changes made by the previous National government."
He said serious harm matters could take two years or more to be dealt with, so to suggest there had been a spike since the election did not take that into account.
The latest New Zealand Crime and Victims Survey found 4 percent of the population experienced nearly half of all crimes - and that young people, Māori and those with mental health issues were more likely to be victims.