Prime Minister Jacinda Arden this afternoon announced Andrew Coster as the next Commissioner of Police.

Existing Commissioner Mike Bush will step down in April after serving six years over two terms.

The shortlist of four contenders - John Tims, Sandra Venables, Coster and Mike Clement - were interviewed by the State Services Commission selection panel in December.

Coster, who joined the police in 1996, is the youngest of the remaining candidates and has an LLB (Hons) and a masters degree in public management.

Currently an acting Deputy Commissioner, Coster has frontline experience as the area commander for Auckland Central, followed by a shorter stint as the Southern District Commander, which covers Otago and Southland.

He was personally thanked by Police Minister Stuart Nash in Parliament during the final reading of the bill which banned semi-automatic firearms following the terrorist attack on two mosques in Christchurch.

"Andrew takes up this leadership role at a time when the Government is making our communities safer by adding 2,000 new police officers to the frontline and reforming gun laws to stop firearms from falling into the wrong hands," Ardern said today.

"I know he'll lead a team of 13,000 people across the country with positivity, inclusion and integrity.

"I first met Andy in his role in Central Auckland. I've had the opportunity to see him work on policy issues such as recent gun law reforms, but most of all I've observed his passion for a police force that knows its strength lies in what it can achieve with the community it serves.

"I want to thank Mike Bush MNZM who has led the Police for six years including during the significant affront to the safety of New Zealanders that occurred on March 15," Jacinda Ardern said.

Police Minister Stuart Nash said Andrew, who is currently Acting Deputy Commissioner, Strategy and Partnerships and who has dedicated nearly 25 years to police service, was incredibly deserving of the role.

"The Commissioner of Police is focused on preventing crime and making our communities safer," Nash said.

"Andrew Coster has a strong history of accomplishments following his graduation from Police College in 1997, including serving in frontline and investigative roles in Counties Manukau and Auckland.

"He rose to Area Commander in Auckland City Central before becoming the District Commander for the Southern Police District in 2013.

"On moving to Police National Headquarters in 2015 he was Assistant Commissioner, Strategy and Transformation. Before taking up his current role, he was Acting Deputy Commissioner, Resource Management.

"He has been a Solicitor in the office of the Crown Solicitor in Auckland, and more recently was seconded as Deputy Chief Executive at the Ministry of Justice," Nash said.

Coster has been appointed for a five-year term from 3 April 2020.