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.
Officials who are expert in the honours system had detailed the process to be followed in an email to Prime Minister Jacinda Ardern's office when Brierley was first 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 - an expertise on which they were called to provide when news of Brierley's arrest was first made public.
Emails released through the OIA show the Prime Minister's office was immediately bombarded with questions about Brierley's knighthood.
In response, Rachel Hayward - Deputy Secretary of the Cabinet - told the Prime Minister's office there were a series of triggers that 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 "situations where the holder of an honour is sentenced to more than three months in prison" and "the offence involved other disgraceful conduct such that public opinion would consider it wrong for the offender to hold a Royal honour".
The OIA response showed the Prime Minister's office had received multiple emails calling for Brierley's knighthood to be removed.
Barrister Denise Ritchie, founder of the Stop Demand group named for its objective of halting the sex trade through 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 get ahead of the process by resigning his knighthood. "In such a case the Queen would be informed, with no further action needed."
Brierley entered guilty pleas to three charges and an additional 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. 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.
