Newshub also spoke to the manager of a central Auckland backpackers, who didn't want to be named, who said their hostel, as well as others, were in a similar boat. They have dormitories where multiple people sleep as well as kitchens for all guests to cook in.

"It is impossible to self-isolate in a backpackers as it is shared facilities. It's basically, or it's literally, you cannot stay here," the manager told Newshub.

"We have had people who have basically tried to check-in, who have come from the airport, and we have basically turned them away and said you cannot stay here."

On Tuesday morning, among the foreigners turned away, was a group of four from Poland.

"They basically came from Poland, to Australia and then into Auckland. They are in New Zealand for 12 days. When they tried to check-in, I said, look, you're going to be sitting in a room for the next 12 days, you are not going anywhere, you've got to self-isolate."

Groups like Hostel World have information on their websites about travel restrictions, including links to different countries' advice. The manager Newshub spoke to also said they understood booking companies were sending emails to travellers telling them of the self-isolation rules.

On top of being required to register with Healthline, the Ministry of Healths says people coming into New Zealand must fill out health cards. There is also a telephone follow-up and spot checks will be conducted.

Additionally, Director-General of Health Dr Ashley Bloomfield said on Tuesday travellers' arrangements would be scrutinised at the border.

"Now we have health staff at the border before the Immigration and Customs desk, and they are looking at the health declaration of every person coming in and quizzing them about their plans for self-isolation.

"And if they are not convinced that the person has concrete plans, or if the person is objecting to self-isolation… we have either police staff or Customs officials there who can make a decision about whether that person gets let into the country in the first place."

He added there are multiple ways the public can alert health officials to travellers who claim they will ignore the new self-isolation rules.

If the person is at the airport then Customs officials can be notified. If the traveller has left the airport and isn't self-isolating, people can contact Healthline or let the police know.

"Usually people, after a discussion about why the requirement is there and what the expectations are, are willing to comply," he says.

According to the hostel manager, the group of travellers from Poland claimed to not know of the self-isolation requirements.

"They said they weren't aware of it. [But] one of them would have got the email saying this is what the situation is."

The manager told Newshub they wished officials at the border wouldn't allow the travellers to continue on to the hostel and was concerned about the method of transport they would have taken. According to the Ministry of Health, public transport can be used "for the sole purpose of returning to your home".

"To be perfectly honest, they shouldn't have even got to the backpackers in the first place," the manager said.

"They should have been stopped at Customs and [told] you can't stay there, you need somewhere where you can have your own room, where you're not going to be sharing facilities with other people."

The manager said the hostel was happy to provide refunds if a group is forced to cancel.

"It is a really shitty situation for everyone, so I don't think anyone should be punished for it. The hospitality industry on a whole is going to be punished, just due to the fact that tourism is dropping."

On Monday, Prime Minister Ardern said she had zero tolerance for anyone not self-isolating in New Zealand. Anyone flouting those rules could be deported.

"Cabinet has been approved for temporary visa holders to be liable for detention and deportation if they do not comply with instructions," Ardern told media.

Her warning comes after two tourists told Newshub on Monday morning they did not intend to self-isolate and would continue travelling around the country in a campervan.

They said they would try and keep their distance but would be taking no serious measures.

"A message and warning for anyone who visits here - We will look after you if you look after us," said Ardern.

"But if you come here with no intention of self-isolating then frankly you are not welcome and you should leave before you are deported."