The barrister for One Nation's Malcolm Roberts has for the first time revealed that his client was sent and completed official UK forms in an effort to renounce dual British citizenship.
It's an important detail that complicates the changing citizenship story of senator Roberts who, when questions were raised last year, had originally declared that he had never been a British citizen.
Since then, Roberts has revealed he was in contact with the UK Home Office around the time of last year's election, while BuzzFeed News uncovered his Australian citizenship application form from 1974 which showed Roberts signing that he was British.
Roberts is one of five MPs — along with Barnaby Joyce, Matt Canavan, Larissa Waters and Scott Ludlam — who have been referred to the High Court after it was revealed they were dual citizens and possibly ineligible to sit in the Australian parliament.
On Thursday, High Court chief justice Susan Kiefel held the first hearing relating to the citizenship mess which has engulfed Australian politics.
Barrister Robert Newlinds revealed that along with emailing the UK Home Office in the lead-up to last year's election, the One Nation senator was sent and filled out official renunciation documents.
"The election then came and went," Newlinds told the court. "At a time — that I haven't quite got my head around in the chronology — the Home Office sent him a form to fill in.
"He filled that in and sent it back. At a later time he received correspondence from the Home Office saying they accepted his renunciation."
Newlinds then told Kiefel that it was unclear whether the UK had renounced Roberts' UK citizenship due to the emails or the official forms.
"It's unclear whether they were accepting the renunciation by the form or the earlier email."
The official documents didn't come up during a tell-all interview that Roberts did with Sky News host Paul Murray at the end of July.
Roberts provided a timeline of his contact with the UK Home Office, which apparently resulted in a "registration" of his renunciation in December 2016, months after the election.
His office also continued to insist that the senator never "believed" he was British.
But the week after the Sky News interview, BuzzFeed News found Roberts' official application for citizenship in the National Archives, where the 19-year-old future senator clearly signed that he was British.
In court on Thursday, the Commonwealth solicitor-general Stephen Donaghue said this citizenship document meant that Roberts' case to answer was very different to the other MPs.
"There is in the papers transmitted to this court from the Senate, a document that is an application for Australian citizenship made by Mr Roberts when he was 19-years-old that says he was a citizen of the United Kingdom and the Colonies at the time," said Donaghue.
“If that fact is correct, then he falls into the category of a person who knew at one point in time that he was a foreign citizen, and therefore ... did he take all reasonable steps [to renounce]?”
At the end of Thursday's directions hearing, Kiefel said all the MPs under a citizenship cloud will be heard before the High Court from October 10 for three days.
Mark Di Stefano is a media and politics reporter for BuzzFeed News and is based in London.
Contact Mark Di Stefano at firstname.lastname@example.org.
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