A Health and Safety Executive report earlier this year suggested that poor maintenance was the most likely cause but did not provide a definitive answer.
Moayedi's salary was cut from £595,000 to £491,000. No decision has been made as to whether the suspended bonuses will be paid retrospectively once the question is resolved.
Commercial director Rob Johnson was the only board member to get a bonus. He received £50,000, taking his total pay to £147,000. Johnson received the sum because of a contractual arrangement agreed before he became a director.