"Imagine, you know who you are, and someone else telling you that you are not that person. It is very stressful."
Mr McHugh, who was born in the Cook Islands, was adopted by an Australian couple when he was six years old and spent his childhood in Toowoomba, Queensland, where his birth was registered.
The 52-year-old did not discover he was adopted until 2013, when he was 45 years old and after fathering seven children.
Years later, in 2017, Mr McHugh successfully applied for an Australian passport, which reinforced his belief that he had obtained citizenship through adoption.
But after he was sentenced to nine months jail for aggravated assault and threatening to kill a person the following year, Mr McHugh was shocked to hear he would be deported to New Zealand under section 501 of the Immigration Act due to a criminal conviction.
“It is quite baffling, I was Australian until they wanted to kick me out,” Mr McHugh told SBS News in 2018.
The Department of Home Affairs told Mr McHugh that he had never applied for citizenship by descent and that his adoption did not make him an Australian citizen because it happened before a law was changed in 1984 to allow automatic citizenship via adoption.
Mr McHugh was in Australia on an Absorbed Person Visa, according to the department, which was revoked following his prison sentence. In August last year, Immigration Minister David Coleman, who is currently on personal leave, rejected his bid to have the cancellation overturned.
But Justice Stewart Anderson on Thursday ruled that the Immigration Ministers' decision not to overturn the visa cancellation was "unreasonable" and directed Mr Tudge to reconsider the case.
"The Minister failed to acknowledge the registration of the applicant’s birth in Queensland or the issue of the applicant’s Australian passport, and otherwise failed to engage with the circumstances underpinning the applicant’s belief in his Australian citizenship," the judgement read.
"These failures led to the minister making a decision that was, in a legal sense, unreasonable."
Mr McHugh is currently detained at Melbourne's Immigration Transit Accommodation.
With Jarni Blakkarly