A plane was forced to delay disembarking after fears that unwell passengers on an Air New Zealand flight could be infected with norovirus.

An Air New Zealand flight was forced to stay on the tarmac at Christchurch Airport amid fears some passengers were infected with norovirus.

The Wednesday morning flight from Queenstown to Christchurch was held up while the airline sought medical advice over unwell passengers who said they'd been exposed to the viral gastric infection.

Canterbury public health authorities assessed the situation and gave the all clear for the passengers to disembark, an Air New Zealand spokeswoman said.

But the unwell passengers who were part of a 40-strong tour party have been told they can't travel until they are well again.

Symptoms of the viral superbug include nausea, vomiting, abdominal pain and diarrhoea, and usually show up about 10 to 50 hours after contracting the virus.

The virus can spread through eating contaminated food, touching contaminated surfaces, or having direct contact with an infected person.

Copyright AAP 2014.