Staff of two senior federal government ministers colluded to make sure cameras captured the moment union offices were raided, in a move aimed to hurt Opposition Leader Bill Shorten.
Senator Michaelia Cash's former media advisor admitted on Wednesday that he and a staff member of ex-justice minister Michael Keenan tipped off news outlets about raids of the AWU's Sydney and Melbourne offices in October 2017.
The raids were part of investigations into the legality of $100,000 donations the AWU made to left-wing lobby group GetUp! in 2006 when the union was led by Mr Shorten, who also sat on the lobby group's board.
David de Garis, ex-adviser to Senator Cash, told the Federal Court on Wednesday he and the then-justice minister's media adviser Michael Tetlow tipped off the media about the raids.
"I spoke to a media advisor in the office of the justice minister," Mr de Garis said.
"I understood the raids were going to occur in the offices of the AWU in Melbourne and Sydney and we organised to disseminate the information to the media together."
The pair decided "amongst themselves" about who they would contact in the media.
"I called several print journalists. Mr Tetlow was calling the TV media," Mr de Garis said.
Earlier on Wednesday, Mr de Garis admitted the media attention was at least in-part designed to make Mr Shorten look bad.
"It would have at least been part of my thinking, I'm sure," he said when asked if the impact on Mr Shorten was part of his consideration to tell the media.
Camera crews showed up at the union offices before Australian Federal Police in a move that raised questions about the motivation behind the raids.
In parliament on Wednesday, Mr Keenan stood by previous comments that no one in his office informed media outlets before the raids.
"We had protocols associated with dealing with (sensitive) information and we continue to make sure those protocols were adhered to in all circumstances."
Labor pounced on the conflicting reports.
"There is somebody lying - either the former advisor of Minister Cash, under oath, is lying to the court or Minister Keenan is lying to the parliament," opposition MP Brendan O'Connor said.
In the upper house, Senator Cash refused to comment on the matter while it was before the court.
She is due to give evidence in court on Friday.
The AWU is arguing, in its case against the Registered Organisations Commission and AFP, that the raids were unlawful.
It's alleged they were politically motivated and instigated by Senator Cash in a bid to hurt the union and Mr Shorten.
Mr de Garis has previously told the trial he was given information about the impending raids by the senator's then-chief of staff, Ben Davies.