Australia has suspended its travel bubble with New Zealand for three days after a confirmed case of a highly transmissible Covid-19 variant was identified in a woman who had been out and about in the community.

The 56-year-old likely contracted the virus from someone on the same floor of the Pullman hotel in Auckland, where they were both quarantining.

New Zealand health authorities are concerned because the woman had left the hotel after serving her full quarantine period and after producing two negative test results.

It was only later that she developed symptoms and returned a positive test – raising concerns she may have unknowingly spread it to others in Northland and Whangarei.

On Monday, New Zealand authorities revealed the woman appeared to have a variant of the virus first identified in South Africa, known as B1351, which has an unusually high number of mutations and appears to be more transmissible than other variants.

The Australian health minister, Greg Hunt, on Monday said “Australia has suspended green zone travel arrangements with New Zealand for a minimum of 72 hours whilst more is learnt about the transmission”.

“This change comes into effect immediately,” the minister said in a statement.

“The decision has been taken out of an abundance of caution to reduce the risk of this variant, which has been shown to spread more readily between individuals, entering the Australian community.”

All green safe travel zone passengers from New Zealand currently en route to Australia, or with planned travel to Australia in the next 72 hours, will be required to enter mandatory hotel quarantine for up to 14 days on arrival.

But Hunt said New Zealanders should reconsider their need to travel altogether. Anyone who has arrived in Australia on a flight from New Zealand on or since 14 January has been asked to isolate, get tested and to remain in isolation until a negative test is returned.

The New Zealand director general of health, Dr Ashley Bloomfield, announced additional testing sites had been established in Northland and Auckland. The woman who tested positive left hotel quarantine on 13 January and travelled home to the Northland region. She started developing mild symptoms on 15 January and they progressively got worse. The woman was tested on 22 January and self-isolated at home.

Bloomfield urged people who had visited one of the 30 locations of interest identified by authorities or who were displaying symptoms to get tested.

“There are a lot of people turning up in Northland who are neither symptomatic nor were at the places,” Bloomfield said. “Can I ask those people to stand back and ensure that those who are the priority to be tested first.”

The New Zealand prime minister, Jacinda Ardern, said Scott Morrison advised her the travel bubble was being suspended.

“I was advised late this afternoon of Australia’s decision by the prime minister,” she said. “I advised him that we have confidence in our systems and processes but it is Australia’s decision as to how they manage their borders.”

Additional reporting Eleanor de Jong