Prime Minister Jacinda Ardern has not ruled out an apology to those affected by the Government's MIQ lottery system in light of a High Court ruling that found some aspects operated "unjustly". 

Advocacy group Grounded Kiwis took up a case against the Government's operation of MIQ at the end of last year under the lottery system, where for majority the chance of earning a return home was purely up to luck. 

In a decision published last week, Justice Jillian Mallon found that although MIQ was a critical component of the Government's elimination strategy, the combination of the virtual lobby and narrow emergency criteria meant New Zealanders' rights to enter their country was infringed. 

"In some instances in a manner that was not demonstrably justified in a free and democratic society," Justice Mallon said. 

Mallon found that the MIQ system, focusing over the period from September 1 last year to December 17, didn't allow for individual circumstances to be considered and prioritised, and examples of extreme delays were not prioritised. 

The MIQ booking system did not allow for individuals, and the prioritisation of returning citizens, due to the "virtual lobby" that operated as a lottery and the criteria for emergency allocation was narrow and too tightly set. 

Ardern said a declaration on relief reached by the parties had not been made yet, but there would be "more to say" after that. 

"We've known and acknowledged that MIQ and the systems we put in place to manage MIQ were the best of a range of bad options. 

"The moment we're limiting the ability to come into the country, you are going to have a situation where people are put in terrible scenarios, and we've seen countless stories of that and all of them have been heartbreaking and incredibly difficult." 

Asked if she would apologise to those affected, Ardern said she didn't want to "delve into the space" while the court was still to make a declaration. 

"I want to make sure that we have the declaration... I do think there will be more to say. 

"One thing I would acknowledge is that our attempts to make it fairer were found obviously by the court to not have improved the system, and I accept that."