New Zealand's "first bloke" Clarke Gayford has revealed how he battled an angry shark while filming on a recent diving trip.

Gayford, partner of New Zealand’s Prime Minister Jacinda Ardern, was diving off Auckland on the country’s North Island when he encountered a large bronze whaler shark.

The 40-year-old broadcaster, who presents TV fishing show Catch of the Day, tweeted a photo showing him fighting off the predator with a pole, as a dolphin watched on in the background.

He joked “a childhood myth is ruined” after the dolphin failed to come to his assistance, highlighting their centuries-long reputation for protecting humans in trouble at sea.

“So it turns out that not only do dolphins not help, they actually quite like watching,” he posted on 16 May.