Matthew Niall, an Australian man who obtained an Irish passport when he was 19, has discovered that he was stripped of his Australian citizenship more than 20 years ago for obtaining a different passport. 

Matthew Niall, who was born in Sydney and lived in Australia until he was 21, revealed that he applied for an Irish passport when he was 19 to help him travel and work in Europe. 

Niall, who qualifies for Irish citizenship through his grandfather, received his Irish passport in September 2001. 

However, he unwittingly forfeited his Australian citizenship by applying for an Irish passport due to a now-defunct law. 

Under section 17 of Australia's 1948 Citizenship Act, any Australian citizen over the age of 18 will "cease to be an Australian citizen" if they acquire a second citizenship. 

The law was repealed in April 2002, seven months after Niall acquired his Irish passport. However, the Australian Government did not reinstate citizenships that had been lost thanks to the law, leaving Niall without Australian citizenship for more than 20 years. 

Niall told ABC Australia that he always planned to return to Australia but chose to remain in Europe following the birth of his son Alexander in Copenhagen 16 years ago. 

Niall said he had no option but to remain in Europe, even after his relationship ended. 

"He's my son. I couldn't leave him, I didn't want to leave him," Niall told ABC Australia. 

Although Niall remained in Europe, he continued to travel on an Australian passport and vote in Australian elections, while he also obtained Australian citizenship for his son. 

He later had two daughters with a Swedish woman named Louise and attempted to acquire Australian passports for his two daughters in late 2021 as part of his plans to travel to Sydney. 

However, the Australian Department of Home Affairs then informed him that he had lost his Australian citizenship, pointing to section 17 of the 1948 Citizenship Act. 

Niall was given a window to prove he had not ceased to be an Australian citizen but had his citizenship officially revoked last June. His passport has been rendered invalid, and he has additionally lost the right to vote in Australian elections and the right to enter Australia without a visa.

He is also ineligible for overseas consular services, while his son's Australian citizenship has also been revoked because Niall was not technically an Australian citizen at the time of his birth. 

Niall told ABC Australia that it was "devastating" to learn that he was no longer an Australian citizen. 

"If I'd known about this legislation, I never would have done it… It just felt like a nightmare," he said. 

Anyone who has lost Australian citizenship due to the old law can apply to resume their citizenship in a process that costs $210 AUD and takes an indefinite length of time. They must also prove that they are of "good character". 

Niall revealed that he has spent thousands of dollars on immigration lawyers to resolve the issue. 

North Sydney independent federal MP Kylea Tink has written to Australia's Minister for Home Affairs Andrew Giles about Niall's Case, stating that it is "extraordinary" that a citizen could have accidentally revoked their citizenship. 

"Surely if you're in a situation where you are about to sign away your citizenship, that should be something that should be coming up in big flashing lights," she said, describing it as "bureaucracy gone mad". 

"The most straightforward way would be for parliament to remedy the scenario and to recognize that people who may have ... lost their citizenships, to be reinstated as if it had never been lost." 

However, Giles informed Tink that it is not possible to reinstate citizenship, only to resume it. 

"A person who is approved for resumption of Australian citizenship becomes an Australian citizen on the day they are approved to become an Australian citizen again; it does not apply retrospectively to the date they lost Australian citizenship," Giles said in a letter to Tink.