Cabinet minister Linda Reynolds has tested positive to COVID-19 and won't be attending the first parliamentary sitting of the year.
The West Australian senator was expected to attend Tuesday's formal statement of acknowledgement to parliamentary staffers impacted by abuse, trauma and bullying.
The alleged rape of her former staffer Brittany Higgins in her office triggered a major overhaul aimed at cleaning up the toxic culture in Parliament House, including the formal acknowledgement to be delivered by the Speaker and Senate President.
Senator Reynolds is in Tasmania, where she has been on a work visit.
"Upon testing positive, minister Reynolds immediately commenced mandated self-isolation and notified the Tasmanian Department of Health as per local requirements," a spokesperson told AAP.
"The minister will return to parliament as soon as possible and in accordance with relevant public health requirements."