The Health Minister has hit back at criticism health officials are downplaying the threat of COVID-19 transmission at last week's Tool concert.

On Friday, Director-General of Health Ashley Bloomfield revealed one of New Zealand's four confirmed patients attended the legendary metal band's show at Auckland's Spark Arena on February 28.

He was in the general admission standing area near the front - close to, if not in, the moshpit.

But Dr Bloomfield said the chance of the deadly disease being passed on to others was low.

His description of a moshpit as 'casual' rather than 'close contact' however bemused rock fans, who know moshpits can be a heaving mess of sweat, saliva and in some cases, even blood.

"I don't think this doctor understands GA at a Tool concert," Kiwi documentary maker and massive Tool fan David Farrier tweeted.