New Zealand health authorities on Monday admitted they overreacted to an influenza scare on a flight from Japan by quarantining the plane on the tarmac at Auckland airport for several hours.

The Air New Zealand flight from Tokyo was isolated after it landed Monday morning when the airline informed health officials that about 60 Japanese students were displaying flu-like symptoms.

The Auckland Regional Public Health Service put local hospitals on standby for mass patient admissions, as medical teams in biohazard suits entered the Boeing 777-200 to examine the sick passengers.

They were eventually allowed to disembark after about three hours when it was determined that, while some had colds, they had been immunised against flu and did not have the virus.

"In hindsight we overreacted to this but that's better than underreacting. We needed to make it safe until we were sure," health service medical officer Richard Hoskins said.

He said authorities had a duty to treat all health scares seriously.

Stuart Cundy, head of the homestay organisation that is hosting the students, was nonplussed at the fuss his visitors had created.

"I've been travelling with them for an hour-and-a-half on a bus and I haven't heard a sneeze," he told the New Zealand Herald.