When Tim Hollo began his quest for a seat in the Federal Parliament, he never expected it to take a president's signature and a 75-year-old document to renounce his dual citizenships.

He knew from the outset he would have to confront Section 44 of the Constitution — the footnote proscribing dual-citizen politicians that in 2017 felled then-deputy prime minister Barnaby Joyce and 14 others.

But the Greens candidate had no idea his fight for the new seat of Canberra would take him on a 13-month investigation to get to the bottom of seven possible citizenships, thanks to his itinerant ancestors.

"I knew that as the child of refugees, with a pretty complex background, I was going to have an interesting time, but I had no idea how difficult it was going to get or how long it was going to take," he said.

And it came down to the wire: just weeks ago Mr Hollo was prepared to withdraw, because he could not clear a surprise citizenship.

Long journey to Australia

Tim Hollo's paternal grandmother Hermi Milch (in white) with her family in Hungary. The Russian Jewish family were continually forced to flee for their safety. ( ABC News: Jake Evans )

Mr Hollo's mother Carmella Galperin was born from a family of Russian Jews, who fled in the collapse of the Russian Empire to Harbin, China, where they joined a community of hundreds of thousands of Russian Jewish emigres.

It was a relatively safe time for Jews in China, but with the newly-formed Soviet state settling, the family returned to their homeland.

They stayed until Joseph Stalin took power and it became too dangerous to stay in the USSR. The Galperins once more fled to safer country — to Germany, in 1924.

That is where Mr Hollo's grandmother was born.

When Germany turned down its dark path, the Galperins turned back to the Jewish community in Harbin.

But the politics of China had changed and the Galperins were not welcome.

Carmella Galperin was in the care of the UNHCR for a year after being expelled from China. ( ABC News: Jake Evans )

When Carmella was born in 1944, she was stateless.

Her birth certificate was a mingling of Hebrew, Russian and Mandarin, though it was not recognised by the Chinese government.

Though it was no use to her anyway — the Galperins were expelled in the Cultural Revolution.

They spent a year under the care of the United Nations in Hong Kong, before finally settling — this time for good — in Australia.

Tim Hollo's parents came from neighbouring countries, but both families were forced on journeys across the globe, before settling in Australia. ( ABC News: Jake Evans )

In total, Carmella's family left Mr Hollo with five potential citizenships he needed to settle: Russian, Israeli (because all Jewish people are entitled to citizenship), German, Ukrainian (because the region his family came from is now part of the Ukraine) and Chinese.

Some, Mr Hollo was entitled to.

Some, he was not.

Mr Hollo, who was born in the United Kingdom, knew he would have to renounce his British (and sixth) citizenship — that was no issue.

But it was his father's side that turned up a seventh potential citizenship, and some unexpected issues for him.

Tim Hollo's Hungarian problem

Tim's father Andrew Hollo (right) as a young boy with his family in Budapest, Hungary. They were forced to cross to Austria by foot to escape the Soviets. ( ABC News: Jake Evans )

Andrew Hollo was born in Hungary in 1945.

His parents had survived the Holocaust, but when the Russian tanks rolled into town in the 1950s, they refused to take their chances and defected.

Andrew's mother took the young boy and his little brother to a town on the Austrian border, where they crossed by foot to avoid the guards and dogs.

In Austria the Hollos claimed asylum and were sent to Australia, where Andrew was naturalised.

"I had always assumed that because [the Hollos] defected, I wouldn't be entitled to citizenship, I thought it would be struck off," he said.

"The weird thing is in Hungary it's kind of the opposite — they're keen to repatriate people who fled. I automatically became Hungarian even though I didn't know it.

"It took me months of research to find out that I was actually automatically a Hungarian citizen, and then it took many more months, a big effort, searching for documents across the world and lawyers in Hungary to renounce that citizenship I didn't know I had.

"It's kind of nuts."

Over a year and a half, Mr Hollo spent thousands of dollars employing lawyers and translators to help him cut off his ties to Hungary.

The marriage certificate of Tim Hollo's Hungarian grandparents — a 75-year-old document that took months of work to find. ( ABC News: Jake Evans )

In particular, he was asked to find the original marriage certificate of his grandparents, a 75-year-old document written during the war.

And his lawyers had to meet with several Hungarian ministers, who would not easily let go of a citizen.

"Eventually I had to get the signature of the president of Hungary on my renunciation document," Mr Hollo said.

"So the one that turned out to be difficult was the one I thought would be the simplest, which was Hungary."

Ready to stand down

Mr Hollo's renunciation was only cleared at the end of January.

When it looked like an election would be called following last year's leadership spill, and again when it looked like the Government might call an election for March, Mr Hollo readied himself to resign.

Mr Hollo said immigrants should not be shut out of democracy in a multicultural country like Australia. ( ABC News: Jake Evans )

"I was basically getting myself ready to stand down as a candidate, and I would be surprised if there weren't other people around the country doing the same thing," he said.

He said it was a close call for him, even with more than a year to prepare.

And he said those who might sniff the wind of political opportunity this year could end up caught out, because they have not had that long lead time.

"I was lucky. I was able to find a lot of these documents, and I had the support, and I was preparing for it early," he said.

"The point for me is that a basic principle of democracy is access, accessibility. You've got to enable people to run, instead of throwing up barriers."

Mr Hollo believes that ultimately the citizenship barrier needed to be resolved with a referendum.

Though he believed Section 44 could be resolved with thoughtful legislation.

"I think there are ways that the Parliament can change the reading of the Constitution without going to a referendum," he said.

"But it is a priority in that democracy around the world is struggling at the moment … and people are feeling shut out."

In a country of immigrants, he said people who could contest this election as representatives of Australia might end up locked out.

"I'd be very surprised if that hadn't already happened. And if it hasn't already happened, it almost certainly will."