The investigative hearing was used, as far as we know, once, in the course of the Air India trial in 2003, I believe it was. The preventive arrest powers, as far as we know, have not been used. We never used them in that time period.
Evidence of meeting #49 for Public Safety and National Security in the 40th Parliament, 3rd Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was provisions.
A recording is available from Parliament.