A board member from Swedish biometrics firm Fingerprint Cards has stepped down after police took him into custody over an alleged unauthorised disclosure of inside information.Lars Soderfjell and former chief executive Johan Carlstrom were arrested on Monday on suspicion of insider trading ahead of a profit warning by FPC in December.Soderfjell has however also insisted on his innocence of the accusation.”Even if I believe that I am innocent, after careful consideration and with the company's best interest in mind, I have decided to immediately leave Fingerprint Cards' board of directors,” Soderfjell said in a statement.On Tuesday Sweden's economic crime agency said they had been released but that the investigation into market abuse would continue.Also today, Morgan Stanley decreased its Fingerprint Cards stake. It now owns 0.0396 of outstanding shares after selling shares in the firm.FPC was the biggest faller on the STOXX 600 index yesterday, dropping 7.5 percent.