The Human Rights Commission wants the Government to justify temporarily stopping people arriving home from India.
Flights will be put on hold from Sunday, after almost two-thirds of the Covid-19 cases detected in managed isolation over the past 30 days came from India.
Chief Human Rights commissioner Paul Hunt said more information was needed on the reasons behind the suspension, which will be in place from April 11 to April 28.
It is the first time New Zealand has stopped citizens or residents from returning.
"While a public health emergency is a justification for limits to be placed on the free movement of people, any limitation on the rights of New Zealanders to return home must be clearly justified by the Government in accordance with its domestic and international human rights obligations," Hunt said.
The commission could not assess whether the ban was lawful, unless the Government was transparent about its decision, he said.
New Zealand has agreed under the International Covenant on Civil and Political Rights that no one shall be arbitrarily deprived of the right to enter their own country.
The United Nations Human Rights Committee has said there are "few, if any, circumstances in which deprivation of the right to enter one's own country could be reasonable".
Hunt said, "Temporarily banning New Zealanders from returning home from India is a significant limitation on their freedom of movement.
"Clear justification for the limitation on this basic right is vital.
"Regular review of the suspension is also crucial."
Yesterday, Prime Minister Jacinda Ardern said over the past two weeks, more than 60 passengers coming into the country from India tested positive for Covid-19.
There were 90 active cases in managed isolation, so the Indian cases made up a high proportion of the total, Ardern said.
"If that number of people from any country were coming in with Covid, that would give us cause to pause and look at mitigation to reduce that risk.
"This is not country-specific, this is about the cases we are seeing currently from that region," she said.
Covid-19 modeller Rodney Jones said India reported 126,789 new Covid-19 cases on Thursday, and he expected the number could reach 300,000 a day.
Jones, who is part of a newly established scientific group advising the Government, said New Zealand did not want any more than 10 cases a day coming over the border.
"This is not permanent, we get these waves. The problem is the Indian government has been behind the curve on this.
"For instance we've got a big outbreak starting in Uttar Pradesh, there are festivals coming up they're not cancelling."