Financial services firm Life Partners Holdings Inc announced Tuesday that it has filed a lawsuit in Illinois against Charles Schwab subsidiary optionsXpress Inc, its chief financial officer and one of the company’s largest customers for allegedly issuing and selling fraudulent shares of Life Partners Holdings stock, Business Wire reports.

Life Partners is seeking a court order preventing the Schwab subsidiary from creating and selling unauthorized shares of its stock. The company is also seeking court protection from securities fraud, deceptive business practices and civil conspiracy stemming from the unlawful issuance of fraudulent shares, according to Business Wire.