Watch: Did TVNZ reporter drop the A-bomb after weather report?

A TVNZ reporter ended an interview about the weather with a spray of his own – dropping the A-bomb on live television.

TVNZ reporter Sam Clarke was taking part in a live cross from Westport for 1 News Tonight last night. He had completed his discussion with presenter Greg Boyed – but failed to realise the camera was still on him.

He then turned to his right and appeared to shout "you arsehole".

The camera then returned to Boyed, who appeared briefly flummoxed, before composing himself and introducing the next story, by saying "We can...ah... take you now to our next story about the kauri dieback...".

Live crosses can be perilous for TV reporters, though 1 News anchor Wendy Petrie managed to go viral in 2009 when her celebration after nailing a live update was mistakenly broadcast to the nation.

Petrie had just delivered a live update explaining that the jury in the David Bain re-trial was about to return with a verdict.

The camera was still on her as she celebrated with a fist pump and clenched teeth - and the clip became a YouTube sensation.

Wendy Petrie's celebrated fist pump.

Last night Clarke appears to have forgotten the golden rule in broadcasting – treat every microphone as if it was live.

He joined TVNZ last year after studying journalism and has said he "always dreamt of being part of a major news organisation".

TVNZ has said they hired him because he had a great attitude and was a hard worker.