Nikola Anderson gave evidence this week in the ACT Supreme Court trial of Bruce Lehrmann, who has pleaded not guilty to a charge of engaging in sexual intercourse without consent.

Lehrmann, 27, denies claims he was involved in any sexual activity with Ms Higgins, his colleague at the time, in the office of Senator Linda Reynolds after "a drunken night out".

In evidence that can now be revealed following the lifting of a non-publication order, Ms Anderson told the court it was her job to patrol the ministerial wing at Parliament House early on March 23, 2019.

MORE EVIDENCE NOW ABLE TO BE PUBLISHED:

When Lehrmann and Ms Higgins entered the building without their staff passes at 1.41am, she was at a security scanner helping colleague Mark Fairweather.

Ms Anderson said it was "strange" the pair were there at that time on a Saturday morning, and she remembered Mr Fairweather asking them: "Couldn't this have waited til Monday?"

Lehrmann, who had just told another security staffer he had been asked to pick up some documents, replied in what Ms Anderson described as "a relatively nonchalant manner" that it could not.

Once the pair had been identified as staffers for Senator Reynolds, they went through metal detectors and received visitor passes.

Ms Anderson subsequently escorted the pair to the minister's suite, where she left them.

She told the court she was later informed by Mr Fairweather that "something strange was going on".

Ms Anderson said Mr Fairweather had told her Lehrmann had left the building, but Ms Higgins had not.

"[Lehrmann] seemed to be in a hurry to get out," Ms Anderson told the court, adding that the alleged rapist "sort of threw the [visitor] pass" at Mr Fairweather as he departed.

After some time had passed, with no sign of Ms Higgins, Ms Anderson returned to the ministerial suite to conduct a welfare check.

She said she discovered Ms Higgins "lying on her back, completely naked", on a couch in Senator Reynolds' office.

"[Ms Higgins] has opened her eyes, she's looked at me, and she's proceeded to roll over into the foetal position," Ms Anderson said.

At this point, Ms Anderson said, she closed the door and called her boss to describe what she had just seen.

Mr Fairweather also gave evidence, telling the court he had intended to ask about Ms Higgins' whereabouts when Lehrmann left Parliament House.

He said he did not get the chance, however, because the alleged rapist "flicked the [temporary] pass hastily onto the desk" and was gone before he could question him.

The court also heard this week from cleaner Carlos Ramos, who gave evidence of having been asked by his boss to clean the ministerial suite of Senator Reynolds hours after the alleged rape.

Mr Ramos indicated he had only been asked to do "normal cleaning", and nothing "special".

Under cross-examination by Katrina Musgrove, counsel for Lehrmann, Mr Ramos said the suite's bathroom "hadn't been used recently" and the toilet was "not dirty".

He also agreed with the suggestion there were no unusual smells.

Ms Higgins had previously told the court she threw up in the bathroom after the alleged rape.

The trial continues.

MORE COVERAGE OF THE TRIAL: