Police say they will prosecute protesters who marched on to a central Auckland motorway and stopped traffic on Saturday.

Anti-government protesters organised by Destiny Church founder Brian Tamaki and the Freedom and Rights Coalition walked from Auckland Domain to the Southern Motorway.

About noon, police established a traffic stop near the motorway on-ramp at Newton Gully as hundreds of protesters walked up the ramp and on to the motorway.

They first walked on to the southbound lanes, stopping traffic, before managing to get on to the northbound lanes near Market Rd, leading to Waka Kotahi NZTA and police closing those lanes as well.

Auckland Central police area commander Inspector Graeme Anderson said in a statement on Sunday police had started prosecution action but were yet to formally charge anybody.

"Police have commenced the prosecution phase following yesterday's protest activity in Auckland.

"This will involve reviewing information and evidence to identify those involved in offending - including entering the motorway system on foot and other alleged driving-related offences.

"At this time we have not arrested and charged, or summoned anyone in relation to yesterday's protest activity."

Anderson said police were unable to give a time frame for how long it would be until charges were laid.