Prime Minister Jacinda Ardern has asked officials to begin work on a process that could lead to Sir Ron Brierley being stripped of his knighthood.

Confirmation of the step came this afternoon and followed Brierley's guilty plea today to charges of possessing child sex abuse material.

It immediately brought fresh calls for Brierley to have his knighthood stripped, or for him to resign from holding it.

A spokesperson for the Prime Minister said she had asked for officials to put into action the process of judging whether Brierley should forfeit the Queen's honour.

Wellington College is also severing ties with the disgraced businessman after his guilty plea

Brierley, a Wellington College old boy, has a long connection to the school.

The theatre was named after him, as was a sports field. Brierley had donated significant amounts of money to the college.

"Wellington College began removing all signage referring to Sir Ron Brierley from the school following confirmation of his guilty plea. We will be making no further comment at this time," the school said in a statement.

And Cricket Wellington have also confirmed that it was now in the process of reviewing Brierley's life membership of the sporting body.

"Cricket Wellington is shocked to learn of Sir Ron Brierley's guilty plea to possession of child sexual abuse material at a Sydney court hearing earlier toda," it said in a statement.

"Cricket Wellington has not received donations from Sir Ron Brierley since October 2017. Cricket Wellington will not be commenting any further until the review of Brierley's Life Member status is complete."

Brierley's knighthood

Officials who are expert in the honours system had detailed the process to be followed in an email to Ardern's office when Brierley was arrested, according to documents released under the Official Information Act.

The documents show that ultimately it would fall to Ardern to advise the Queen that the knighthood should be removed.

That is a move that would come after advice from the Honours Unit in the Department of Prime Minister and Cabinet.

The Honours Unit is the specialist team inside the Cabinet Office, staffed by public servants expert in the arcane-seeming world of Queen's honours and awards.

Their role is to provide neutral and solid advice to the Government - expertise they were called to provide when news of Brierley's arrest was made public.

Emails released through the OIA show the Prime Minister's office was immediately bombarded with questions about Brierley's knighthood and calling for it to be removed.

Rachel Hayward, deputy secretary of the Cabinet, told the Prime Minister's office a series of triggers could cause Ardern to ask the Queen to cancel the knighthood.

Her advice was not specific to Brierley but in response to questions about his knighthood.

She said triggers included a situation where "an individual's actions are such that, if they continue to hold that honour, the honours system would be brought into disrepute".

Examples included honour-holders sentenced to more than three months in prison and if "the offence involved other disgraceful conduct such that public opinion would consider it wrong for the offender to hold a royal honour".

Barrister Denise Ritchie, founder of the Stop Demand group, which aims to halt the sex trade by reducing those seeking it out, said the guilty plea made the process to remove the knighthood straightforward.

Ritchie - who referred to Brierley as "Mister Brierley" - said the criteria had been met and the process to remove it should begin now.

"Young lives have been irreparably damaged as a result of this predator's behaviour. This is an abhorrent trade in the rape and molestation of children that is fuelled by male demand. It should be denounced in the strongest terms."

She said Brierley could resign his knighthood. "In such a case the Queen would be informed, with no further action needed."

Brierley pleaded guilty to three charges and 14 charges were withdrawn.

"My client admits he is in possession of some of the images," his lawyer, Lisa-Claire Hutchinson, told the Downing Centre Local Court, saying there was a dispute over the actual number of images on Brierley's devices.

"The figure, which is particularised on the charges that have been certified and committed for sentence, is in dispute. It is the quantum of the images."

Brierley, 83, appeared in court with two lawyers, a security guard and no one else. He looked frail and walked with a cane for support. His lawyers did the talking.

The case was set down for a fresh hearing on April 30, although it was unclear if that was when sentencing would take place.

After the brief hearing, Brierley donned a surgical face mask before leaving the court. He did not answer questions about his plea and left in a chauffeur-driven car.

The three charges he pleaded guilty to relate to child sex abuse material seized from devices Brierley had when stopped at Sydney Kingsford Smith Airport in December 2019, and material found during a search of his waterfront Sydney mansion.

The search by the Australian Border Force followed a tip in August that year to New South Wales police.

One charge to which Brierley admitted identified the offending material as including images of children ranging in age from 2 years to 15 years.

Brierley was preparing to board a flight to Fiji when he was stopped by Australian Border Force officers.

It led to searches of devices at the airport and nearby Mascot police station, and at his mansion in the exclusive Pt Piper suburb.

Brierley has been on bail since his arrest, with the same conditions continuing after his guilty plea. Those bail conditions have allowed him to stroll nearby Double Bay and drive around Sydney's eastern suburbs.

The Herald recently identified that Brierley still appeared to have internet access with an email emerging from him sent in February 2020.

Brierley has enjoyed a towering role in Australasian business for decades. It was a rise that began in the 1960s as he built a business identifying and then buying into asset-rich companies that offered low return to shareholders.

By the 1980s, Brierley's business had extended beyond New Zealand to Australia, and then on a global footing through the 1990s and onwards. In 1988, while chairman of the Bank of New Zealand, his contribution to business and philanthropy led to a knighthood.

text by David Fisher and Liam Mendes, NZ Herald