10.13pm: Confirmation that 11 Rangitoto College students have swine flu is no reason for the public to panic, health officials say.

Health Minister Tony Ryall tonight announced the World Health Organisation had returned positive swine flu results from three of the 11 Rangitoto College students who had tested positive for influenza A.

That was enough to assume all 11 were positive.

However, Director of Public Health Mark Jacobs said the general public was at no greater risk of contracting swine flu than any other type of flu.

"There is no indication it is any more or less contagious than any other form of influenza," he said.

It was most contagious a day before symptoms appeared and up to seven days after. The greatest risk was in the early days.

No age group was any more or less at risk, Dr Jacobs said.

"So far there doesn't seem to be any particular age group that is showing up although, again, as numbers increase around the world we'll get more and more good information on that.

"The reports from Mexico are that it is affecting all age groups."

Dr Jacobs urged people to keep the illness in perspective and said anyone not directly exposed to it was unlikely to contract it.

9.12pm: Tests have "unfortunately" confirmed at least three New Zealanders have tested positive to swine flu, Health Minister Tony Ryall announced tonight.

Melbourne tests on 10 Rangitoto College students who tested positive for influenza A came back from the World Health Organisation (WHO) laboratory tonight confirming three have swine flu.

Tests on a fourth sample were continuing.

The swine flu virus has killed close to 150 people in Mexico and infected dozens in the United States, Canada and Europe.

The Rangitoto students returned on Saturday from a trip to Mexico.

6.30pm: The result of tests on 10 Rangitoto College students who tested positive for influenza A are expected from the WHO laboratory in Melbourne tonight and an 11th member of the group has also tested positive for influenza A.

Mr Ryall made a ministerial statement when Parliament sat at 2pm, and told MPs all 10 of the students who tested positive for influenza A after visiting Mexico were on the road to recovery.

But this evening Auckland Regional Public Health Service (ARPHS) clinical director Julia Peters said that one more member of the quarantined Rangitoto College group had been confirmed with influenza A.