Senator John Faulkner has claimed he has been "spied on" by an arm of the bureaucracy in Canberra.
The matter relates to the use of images from surveillance cameras inside Parliament House and involves a suspected whistleblower who may have passed on information about the public service to the Labor senator.
In a fiery public hearing of a Senate committee, Senator Faulkner confronted the head of the Department of Parliamentary Services, Carol Mills, over the use of CCTV images against DPS staff.
In a half-hour long grilling, Ms Mills confirmed that a potential breach of the rules around the use of CCTV had occurred during a disciplinary investigation into a former staff member working in Parliament.
ABC has more details: they used CCTV to find out which Senator's door they pushed an envelope under. Its now been escalated to a complaint of breach of Privilege - interfering with people communicating with Senators being a classic contempt of Parliament.