Breaking news... the 6pm bulletin is late

The TVNZ building in Auckland. Photo / Doug Sherring

A rare technical glitch was the cause behind last night's One News delay to air.

The 6pm bulletin was delayed for several minutes after a fault was identified with the news studio sound desk.

A spokeswoman for TVNZ confirmed the studio's production team made the discovery just minutes before they were due to go live.

"As a result, we're reviewing our processes to make sure this doesn't happen again,'' the spokeswoman said.

She acknowledged there have been delays in the past, particularly when there are major events or breaking news items which warrant a bulletin to start later.

However, last night's technical glitch was "very rare,'' she said.

A former TVNZ technical operator who worked at the broadcaster for several years said the news delay was extraordinary.

"I imagine there would have been substantial panic at the TV station this evening," he said.

It's not the first time the bulletin has been delayed. Memorably, the One Network News was delayed for about 10 minutes in 1995 after a group of Maori protesters stormed the newsroom minutes before the 6pm broadcast was to air.

Members of the group were unhappy about the fact Maori current affairs programme Te Karere had not been aired over the Christmas break.

Protester Ken Mair said at the time: "From our point of view, Maori news should receive the same time allocation as the Pakeha news. It's as simple as that - and that's why we're here.''

The protesters were later escorted off the TVNZ premises by police officers.