"I'm a good person, but I've done drugs, I've had illicit sex," says Michael Godfrey.

The dean of Napier Cathedral has been stood down by the Anglican Church – for an affair he had 25 years ago.

Michael Godfrey says he confessed his adultery years ago, and felt the church had not offered him redemption.

However the Church claims it was the first the New Zealand clergy had heard of it.

CHRIS HILLOCK/ FAIRFAX NZ Bishop Andrew Hedge has headed the Waiapu diocese since 2014.

He was a 30-year-old married priest when he had an affair in 1991 with an 18-year-old woman in Australia.

"What I have been is always upfront about my feet of clay," he said on Thursday, after being banned from performing priestly duties by the Bishop of Waiapu, Andrew Hedge.

"I've counselled people who have done the same thing that I've done. I've never in my time as priest claimed that I'm faultless.

"I'm a good person, but I've done drugs, I've had illicit sex."

He said Hedge broke the news to him on Wednesday, but he had known since February that he was under investigation.

Godfrey, originally from the Kapiti Coast, claimed he informed his bishop in Australia 25 years ago about the 10-day affair, and had not strayed since.

Both his former and current wives already knew of the adultery, and he was baffled as to why it was being dredged up decades later.

"It happened in my history. I made a mistake, I've never denied that to anybody ... it was absolutely a [mistake] and I'm not making any excuses for what happened.

"I've done as much chastising of myself as humanly possible over the years."

He said his wife was "pretty gutted". "This is something that obviously we've worked through."

The couple have been told they have six months to leave their church accommodation at Napier's Waiapu Cathedral of St John the Evangelist, where he has been dean for almost three years.

On Thursday night he was packing his bags for Australia, where he hoped to wait out the fallout from his shock dismissal.

He said he was informed last year that he was investigated during Australia's Royal Commission into Institutional Responses to Child Sexual Abuse.

He claimed he was cleared during the inquiry, and never was able to learn much of the nature of the allegation against him, nor who his accuser was.

A statement issued by Hedge's representative stressed that Godfrey's sin was not a criminal act, but a breach of church law.

"The decision is the outcome of a church disciplinary process for a historic matter of behaviour, unrelated to the Diocese of Waiapu, deemed to be a breach of church canons, rather than illegal, and not expected of a priest in the Anglican Church."

Godfrey has been a priest for 27 years. He was vicar of Christ Church in Whangarei from 2007 to 2011.

He said there was a "difference in opinion" between the church and him as to whether the matter of his affair was flagged up appropriately in New Zealand. He was considering whether to fight the decision.

"My feeling is that there hasn't been due process or natural justice in terms of the process of dismissal."

The church's website lists Godfrey as being "on leave".

A spokesman for the Anglican Church said Godfrey may have informed his Australian bishop of his extramarital affair, but "it is the first that his bishop, now in New Zealand, has heard of it".

There had been a thorough investigation into the matter, and it was inappropriate to comment on how it was brought to the church's attention, he said.

The length of Godfrey's stand-down had not yet been decided, but once it was over, the "door is open for him to come back".