Labor senator Stephen Conroy has vowed to continue his fight to stop police accessing thousands of pages of documents relating to the National Broadband Network, despite his shock departure from Parliament.

The veteran Labor powerbroker and former communications minister, whose 20-year Senate career officially finishes on Friday, said there were "fundamental principles" at stake and the documents must remain sealed.

Australian Federal Police officers sensationally raided Senator Conroy's office during the federal election campaign and later executed a search warrant at Parliament House to access the building's email servers.

Senator Conroy has claimed the seized documents are protected by parliamentary privilege and the matter has been referred to the high-powered Senate Privileges Committee for consideration.