Prominent crossbench senator Nick Xenophon is confident he has never held Greek or Cypriot citizenship.
The South Australian insists he contacted the Greek embassy and Cypriot High Commission in 2007 to renounce any citizenship claims.
But Senator Xenophon is not certain there's any official documented response to his renunciations.
"I'd have to go through literally boxes and boxes of archives from an election campaign 10 years ago," he said
"I have never had citizenship of another country, never wanted citizenship of another country."
Senator Xenophon was born to Greek and Cypriot parents at the Burnside War Memorial Hospital in Adelaide.
Senator Xenophon said his understanding from other MPs in a similar position was that those making such citizenship inquiries often don't receive a response.
"The issue of whether an MP is a dual citizen or not will be a festering farce until there has been a full audit of all MPs and senators and there needs to be a resolution through the High Court."
Labor senator Sam Dastyari appeared at the end of Senator Xenophon's doorstep for what looked like a set piece.
"I am not an Iranian citizen," Senator Dastyari said in Farsi.
"I am not a Greek or Cypriot citizen," Senator Xenophon said in Greek.
"We're feeling much more Aussie than our colleagues today," Senator Dastyari said in closing.
