No policy of long term insurance business shall after the expiry of two years from the date of the issue of the policy, be called in question by any insurer on the ground that a statement made in the proposal or other document on the faith of which the policy was issued or reinstated, or in any report of a medical officer or referee, was inaccurate or false, unless the insurer shows that such a statement was made on a material matter or suppressed facts which it was material to disclose, and that it was fraudulently made by the policy holder and that the policy holder knew at the time of making it that the statement was false or that it suppressed facts it was material to disclose :