South Korea’s financial watchdog, the Financial Supervisory Service (FSS), announced on Tuesday that it will investigate the fierce battle for control of Korea Zinc, the world’s largest zinc smelter. The investigation will focus on possible illegal actions taken by Korea Zinc’s management and its challengers, the private equity firm MBK Partners and Korea Zinc’s largest shareholder, Young Poong Corp.

The FSS stated it will focus on attempts to manipulate Korea Zinc’s stock prices. FSS chief Lee Bok-hyun ordered an immediate review, including scrutiny of rumors about Korea Zinc’s plans to repurchase its own shares and cancel them at a higher price. Lee emphasized that any wrongdoing would result in strict penalties.