NASCAR has suspended Camping World Truck Series driver Shane Sieg indefinitely on Monday.

He is being suspended for violating Sections 12-1 (actions detrimental to stock car racing) and 19 (violation of the substance abuse policy).

Also on Monday, NASCAR reinstated Denise Harmon-Mixon, a crew member of the Nationwide Series who successfully completed a rehabilitation program following a suspension for violating the substance abuse policy.