Simon Bridges' claims of an increase in serious crime are being rubbished by a Queen's Counsel.

The opposition leader says the number of serious harm cases before the courts has increased by 25 per cent since the election.

But Marie Dyhrberg told Mike Hosking that's not what she's seeing, and in fact some crime is lessening.

She says any perceived increase is more likely due to a change in the way assault injuries are recorded.