No, because I'm not finished.
The reality is that the commissioner will have a new offence that he can impose, which is anybody who obstructs his investigations or lies to his investigators will be committing an offence under the act, one that can be prosecuted. That will allow him to cut through the obstruction that so worries you.
You raised the issue of police powers to compel. Police do not have that power. Police who are investigating the most heinous violent crimes cannot force someone to speak against their will.