The word " discovered to be void" ( Sec 65 of the Contract Act ), comprehend a situation in which the parties were suffering from a mistake of fact from the very beginning but had not realised,at the time of entering into the agreement or signing the document that they were suffering from any such mistake and had, therefore, acted bona fide on such agreement. The agreement in such a case is void at the very inception and has only been discovered as a void one.