The article explores how collusion between a regulated company and an unregulated competitor can affect market outcomes. Due to incomplete regulations, the regulator may struggle to prevent collusion and gather accurate information. The study shows that when firms collude under information imbalances, the regulator may not be able to use this information advantage effectively. Collusion can lead to inefficient market outcomes, casting doubt on the effectiveness of anti-collusion measures. Additionally, when different regulators oversee each firm, lack of coordination can further hinder efforts to combat collusion.