Claims have come more needs to be done against those convicted of coward punches.

New Zealand First Leader, Winston Peters is renewing calls for a one-punch law.

It comes after Regan Robson-Khan was sentenced to nine months of home detention after he assaulted Wynton King outside a Christchurch bar last October.

King will never be able to drive, work or play rugby again.

Peters told Newstalk ZB's Canterbury Mornings judges are hamstrung by New Zealand laws

He says there are some occasions where they aren't reading the room.

Wynton's sister Amber told Newstalk ZB's Canterbury Mornings they were shocked when the sentence was handed down.

She says as a family and as a nation, we've all been let down by the justice system.

Newstalk ZB caller Sally, who's son has been assaulted, says the punishments are too low.

She says the person who punched her son originally was sentenced to five years in prison but it ended up being reduced to two.

National's Penny Simmonds told Newstalk ZB's Canterbury Mornings this is proof the Government is too soft on crime.

She says people are suffering from the lack of punishments.

Labour's Tracey McLellan says it could be time to re-start conversations about a new piece of legalisation.

Former Northland MP Matt King joined Tyler Adams on Newstalk ZB to discuss.

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