Google co-founder Larry Page was allowed into New Zealand despite its closed border so his son could receive urgent medical attention, the government confirmed Thursday.

The billionaire's visit had prompted criticism from Prime Minister Jacinda Ardern's political opponents, who demanded an explanation for why he was permitted to enter despite coronavirus travel restrictions.

Immigration Minister Kris Faafoi told reporters Page had applied for a medical exemption "to make sure his son got the treatment that was required".

Health Minister Andrew Little, when questioned in parliament about Page, said an application was approved in January for a child, accompanied by an adult, to be medevaced from Fiji.

He said anyone accepted for treatment is considered to require immediate care and could not be treated locally.

"I'm advised all of the normal steps occurred in this case," Little said.

Ardern said she was not briefed at the time Page was in New Zealand.

Immigration New Zealand general manager of border and visa operations, Nicola Hogg, told AFP that Page "met relevant requirements" to be approved entry.

Larry Page founded Google with Sergei Brin in the 1990s and is listed by Bloomberg as the sixth-richest person in the world
Larry Page founded Google with Sergei Brin in the 1990s and is listed by Bloomberg as the sixth-richest person in the world AFP / Emmanuel DUNAND

"Mr Page is not a permanent resident. Citizenship is a matter for the Department of Internal Affairs. Due to privacy reasons, we are unable to comment further without a privacy waiver."

Hogg did not address the question of whether Page spent two weeks in quarantine, as required of people entering New Zealand.

The billionaire had reportedly been based on an outlying Fijian island during the Covid-19 pandemic.

New Zealand's opposition ACT Party called on Ardern's government to be more open about his visit.

"The Government has questions to answer about why billionaire Google co-founder Larry Page was allowed into New Zealand when desperate Kiwis and separated families can't get through the border," ACT leader David Seymour said.

Seymour said while he had sympathy for Page's situation, there were numerous people with similar issues who could not get in.

"I have had to tell them, 'sorry, but there is no way you can get through the border, government policy will not allow it'," he added.

"New Zealanders stranded overseas who are desperate to get home deserve answers."

Page founded Google with Sergey Brin in the 1990s and is listed by Bloomberg as the sixth-richest person in the world with a reported wealth of $121 billion.