Employment Minister Michaelia Cash says one of her staffers has resigned after admitting he leaked information to the media about the Australian Federal Police (AFP) raids on the Australian Workers Union (AWU).

The Labor Party has accused the government of orchestrating the raids to smear Opposition Leader Bill Shorten.

Senator Cash said the leak took place without her knowledge or authorisation and the staff member has now resigned.

“I am advised that this information [to my office] came from a media source,” she said.

“I was not aware of it at the time and was not aware of it earlier today in [Senate] Estimates.

“This took place without my knowledge and was not authorised by me. I was not notified of the raids until I watched them unfold on television.

“My staff member has now resigned.”

Earlier on Wednesday, Senator Cash repeatedly denied she or her office had tipped off the media ahead of the raids when giving evidence at Senate Estimates.

But she denied she misled the Senate.

“You must acknowledge that knowingly or unknowingly you have misled the Senate” Labor Senator Doug Cameron said.

“No, I have not. I answered the questions put to me based on the knowledge I held at the time,” Senator Cash said.

Senator Cash said her staffer was “very distressed”.

She brushed off questions about whether she would refer the staffer to police.