Buy-side cartels or conspiracies cannot be looked at criminally right now, with the exception of anything related to fixing of wages or no-poach agreements. As my colleague pointed out, they can be looked at under the civil provisions of the Competition Act under section 90.1.
I would point out that whether the Competition Act should be reviewed to be able to look at buy-side cartels under a criminal track is a live issue right now. The government has launched a consultation on the Competition Act, and there are a few notable issues that are taking up a lot of time, and that particular issue is one.
Looking at the buy side under criminal provisions is a long-standing issue in competition law.