That is the view of Prof Mark Henaghan, dean of the University of Otago Faculty of Law, who said such treatment in Australia was ''very harsh''.
''It's almost getting close to Guantanamo Bay,'' he said.
About 780 people captured in the War on Terror were initially held at the Guantanamo Bay detention camp, a US military prison located within the US Guantanamo Bay Naval Base, in Cuba, when the camp was established in 2002.
About 116 detainees remain there.
Australia recently stepped up its policy of indiscriminate deportation of people who have been imprisoned for more than 12 months, under new laws enacted in late 2014.
About 300 New Zealanders are among those awaiting deportation in detention centres, including some in remote facilities such as on Christmas Island, an Australian territory not far from Indonesia.
Prof Henaghan said all countries reserved the right to deport foreign nationals under certain circumstances, including if they had served lengthy prison sentences for serious crimes.
He noted Colin Bouwer, the former Otago University head of psychological medicine, who in 2001 was convicted of killing his wife, Annette, would be deported to South Africa when he was released from jail.
But in this case, Australia was holding New Zealand and other citizens ''in a kind of prison for long periods of time'' before deportation, he said.
Prof Henaghan queried the appropriateness of this long detention, given the detainees had already served their time for any previous convictions.
He queried if this was in keeping with the spirit of the ''special relationship'' between New Zealand and Australia.
There seemed to be a view in some circles in Australia that because New Zealanders and people of other nationalities had broken Australian law, ''we're entitled to treat them as badly'' as was required, he said.
He also took issue with holding some New Zealand detainees in remote places, far from their friends and family, who would be unable to visit them.
Asked about the situation of New Zealanders who had left this country when they were young children and had few memories of this country and few relatives here, he said this also seemed ''unfair''.
It was inappropriate to send some people back to a place they had not seen for decades, in some cases.
This could be a ''totally alien country'' where they might have ''no support or any family''.
''I don't think it's humane,'' he said.
Prof Henaghan also raised Australia's obligations under the Universal Declaration of Human Rights and the United Nations Convention on the Rights of the Child.
Article Nine of the Universal Declaration says no-one shall be subjected to ''arbitrary arrest, detention or exile''.
The preamble to the Convention on the Rights of the Child states that children should grow up ''in a family environment''.
And Article 9 of the Convention says that ''States Parties'' should ensure that a ''child shall not be separated from his or her parents against their will'', unless such separation was ''necessary for the best interests of the child''.
Prof Henaghan noted that in some cases children were remaining in Australia, but at least one of their parents either had been detained or was being deported to New Zealand.
All countries had the right to make their own laws, and ''return'' foreign nationals.
But to ensure fair play, ''a little more attention'' should be given to assessing the the specifics of individual cases, including to ensure human rights obligations were being fully met, he said.
