A freelance journalist is seeking $1.25 million in damages from John Key, claiming the Prime Minister has defamed him.

Photo: RNZ

Bradley Ambrose is the freelance reporter at the centre of the so-called teapot tape incident in November 2011.

He has brought the legal action against John Key in the High Court in Auckland.

According to legal documents obtained by Radio New Zealand, Mr Ambrose says Mr Key made defamatory comments about him on three occasions.

Documents filed by the Prime Minister's lawyer say the comments are true and that they were John Key's honest opinion.

The case is the latest development in the saga of the staged "cup of tea" between the then ACT Party candidate for Epsom, John Banks, and John Key.

Shortly before the 2011 election, major media organisations, including Radio New Zealand, were invited to cover the meeting which effectively saw John Key endorsing Mr Banks to Epsom voters.

Mr Ambrose was one of the reporters covering the event.

The pair posed for photographs at a cafe before heading inside for a cup of tea.

According to court documents, Ambrose left a recording device on the table by accident and it recorded the conversation.

A document filed by Mr Key's lawyer states the Prime Minister believed Ambrose had made the recording on purpose.

Mr Ambrose has always denied this.

Mr Ambrose is asking for $500,000 dollars in aggravated damages relating to comments made by the Prime Minister at a media conference three days after the cup of tea meeting.

The following day, on 15 November, Mr Key gave an interview on TV3's Firstline programme in which he made more comments about the recording.

Mr Ambrose is asking for a further $500,000 over that interview.

The next day Mr Key spoke to journalists in Upper Hutt where he again made comments about the incident. Mr Ambrose is asking for a further $250,000 in relation to that incident.

Radio New Zealand cannot report the comments because that could potentially be repeating defamation.

The so-called teapot tape saga was investigated by police at the time. They found that while the recording was unlawful, a prosecution was not in the public interest.

The Attorney-General was intending to seek more than $13,000 from Mr Ambrose, but that plan was dropped in 2012.

At the time, Mr Ambrose said his reputation had suffered, work had dried up and he was looking at options to fix the damage.

The defamation case will be the subject of a High Court telephone conference in the new year.