The Turnbull government has dodged a potential threat to its knife edge majority after the Greek embassy confirmed backbencher Julia Banks is not a citizen of Greece.
The Liberal Party examined Ms Banks' status on Friday after speculation she may have been a dual citizen because of her parents' Greek heritage and become the latest victim of the citizenship saga.
"We have received confirmation from the Greek Embassy that according to records, Julia Banks is not registered as a Greek citizen and also is not entitled as a Greek citizen," a party spokesman said in a statement late on Friday.
If she was forced to step down under the constitution which prohibits dual citizens serving in parliament, a by-election in her marginal Melbourne seat of Chisholm could have threatened the government's one-seat majority.
Ms Banks' late father Phil Lolatgis migrated from Greece in 1949 as a 15-year-old, while her mother Helen was born in Australia.
"I have never taken up Greek citizenship," she said in a text message on Friday.
LNP senator Matt Canavan resigned from cabinet last week upon discovering his mother had registered him as an Italian citizen without his consent. The issue will be tested in the High Court.
Greens senators Larissa Waters and Scott Ludlam both quit parliament after also finding out they held dual citizenship.
The government is considering asking the Senate to refer One Nation senator Malcolm Roberts to the court over questions about his UK links.
"Obviously if we have a suspicion (about Senator Roberts), we'll check it up," Deputy Prime Minister Barnaby Joyce told reporters on Friday.
Senator Roberts was born in India in 1955 to a Welsh father and Australian mother and came to Australia in 1974.
He said when he was filling out his candidate nomination form last year, he thought it best to double-check.
Senator Roberts wrote to UK authorities, telling them he wanted to renounce any UK citizenship before election nominations closed.
They didn't confirm his correspondence until five months after he was elected.
If found ineligible, his Queensland seat would pass to the third person on the One Nation 2016 ticket, Fraser Anning.
However, Mr Anning is the subject of bankruptcy proceedings due to go to the Federal Court on August 22. Bankrupts are disqualified from being elected.
The fourth person on the ticket is One Nation Leader Pauline Hanson's sister, Judy Smith.