A Sydney teacher and father of three who allegedly led Pauline Hanson to believe her New South Wales election result had been sabotaged has appeared in court.

Sean Castle appeared in the NSW Supreme Court and apologised for not showing up when required to on Wednesday.

"My name is Sean Castle. I have represented myself as being Michael Rattner," he said.

"Firstly, I sincerely apologise to the Supreme Court for my conduct in not attending the court on June 8.

"I've given an undertaking today to the court that I will attend any further hearings as required by the court until excused by the court."

Earlier this week, a warrant was issued for a man identified as Michael Rattner after he failed to appear to give evidence in the case.

He is allegedly the source of leaked emails between NSW Electoral Commission staff that are central to Ms Hanson's challenge.

The One Nation founder ran for the NSW Upper House in the March state election and missed out on a seat by 1,300 votes.

Ms Hanson is challenging the result on the basis of the alleged emails mentioning dodgy staff may have put votes for her in blank ballot piles.

On Thursday, Greens MP Jeremy Buckingham, the man who narrowly defeated Ms Hanson for the seat, raised the possibility she may have been duped after saying he had been contacted by a man claiming to be a journalist.

The man, named Michael Wilson, purported to work for The Daily Telegraph newspaper and claimed to be in touch with Mr Rattner.

But Mr Buckingham said the newspaper confirmed to him that no reporter with that name worked there.

"Mr Wilson first contacted me during the counting of votes," he said.

"He gave me information that indicated he was close to and in regular contact with Pauline Hanson's campaign."

Mr Buckingham believed Mr Wilson and Mr Rattner were the same person.

"He told me I could relax about the case as he had just spoken to Michael Rattner and that Mr Rattner had told him that he would not turn up at court," he said.

"It seems Michael Wilson is the only person who knew how to contact Michael Rattner.

"It now seems to me that Michael Wilson is not only an imposter, but may be the same person as Michael Rattner."

But the plot thickened after Mr Buckingham said Mr Wilson had apparently contacted the commission to request voting figures for himself and another Daily Telegraph journalist, Sean Castle.

"Again, a Sean Castle does not, and has not, worked for The Daily Telegraph," he said.

"Are Michael Wilson, Sean Castle and Michael Rattner in fact the same person?"

- ABC/AAP