One of New Zealand's most high-profile prisoners, who has been behind bars for four decades, will be released.

Arthur William Taylor was granted parole today after being denied 19 times prior. He was due to remain in prison until October 2022.

A New Zealand Parole Board spokesperson told the Herald parole was granted for Taylor at a hearing this afternoon.

His release date will be next month, while a full written decision outlining the Parole Board's reasons will be available within the next two weeks.

Taylor was serving 17 and a half years for charges of explosives, firearms, kidnapping and conspiracy to supply methamphetamine, among other crimes.

The 62-year-old has more than 150 convictions for offences including bank robbery, burglary, fraud and drugs and has spent almost 40 years behind bars.

His first charge dates back to 1972 when he appeared in the Youth Court on a forgery charge.

Taylor's criminal life hit the headlines in 1998 after he escaped from the maximum security prison at Paremoremo north of Auckland with three others, including double murderer Graeme Burton.

The group made their way to the Coromandel, where they hunkered down in luxury holiday homes, including the bach of a multi-millionaire, and the bush to evade authorities.

In recent years he has become better known as the "jailhouse lawyer" after a series of successful court cases.

These included the 2017 prosecution and trial of Roberto Conchie Harris - secret "Witness C" - for perjury at David Tamihere's double-murder trial in 1990.

He then, along with the Herald and other media, fought for the nearly 30-year-old name suppression order protecting Harris to be revoked.

He is now targeting Witness A - the final of three secret witness who claimed Tamihere confessed to murdering two Swedish tourists in the Coromandel Ranges in 1989.

Taylor succeeded in unmasking Witness B as the late Stephen Kapa last year.

He was also instrumental in the courts ruling that denying New Zealand's prisoners the right to vote was inconsistent with the Bill of Rights.

Taylor also challenged the legality of the prison smoking ban.

Despite not wanting to be moved, Taylor was shifted from Paremoremo, a maximum security prison to a residential unit at Waikeria.

Last year, the Herald was granted access by Corrections to interview the infamous prisoner.

"I was like a mastermind of organising criminal activities," Taylor said.

"I'd get a great deal of satisfaction from the rewards and adulation you'd get from criminals. Now I've transposed that into what I do now [where] it is directed in a pro-social and community direction."

He said of his courtroom battles with some of the country's best criminal lawyers: "It just shows you can do it. You learn debating skills, research skills, the analytical skills, all the skills you need to succeed in any field in life."

Last February, Taylor also became engaged to law student Tui Hartman, who had been following some of Taylor's cases.

"She started sending me some messages and we just started taking quite an interest in each other - more than just friends, shall we say," Taylor said.

Timeline

1968:

Placed in Epuni Boys' Home for the first of three stays.

1972: His first conviction was for forging entries in his savings bank deposit book.

1998: Escaped from Auckland Prison with three others.

2001: Released at end of a 10-year sentence. After a life of crime he told the Herald he is now "going straight".

2004: Imprisoned after conviction of drugs and firearms offences and possessing explosives.

2005: Escaped while being taken to a family group conference in Wellington to discuss custody of his child. Assisted by accomplice who pointed an air pistol at two prison officers. Captured after falling through a ceiling onto a "startled" woman in a toilet cubicle.

2006: Smuggled sperm out of prison which he claims successfully impregnated his (now former) wife, Carolyn.

2010: Began series of challenges arguing a ban on smoking on prison property was unlawful. The High Court ruled in his favour three years later.

2015: High Court ruled in Taylor's favour in declaring that a statute that prohibited prisoners from voting is inconsistent with the New Zealand Bill of Rights. The Supreme Court upheld the ruling last year.

2017: Successfully prosecutes Witness C for perjury in the Tamihere double-murder case and later reveals him as Roberto Conchie Harris.

2018: Denied parole for the 19th time.

2019: Granted parole and due for release in mid-February.