hi i am new secretary of old cooperative society , one very serious matter come to me as fallows in our society mr.a purches flat in 1990 from society with reg agreement from society . mr. a sale flat to 2nd person in 2007 with reg agrrememt,but not inform society at all ,not apply for share tranfer on 2nd person . now 2nd person sale flat to 3rd person with reg agreememt but 3rd person want mortgage loan for that 2nd person give him society false noc with false society letter head with duplicate stamp and sign of chairman and secretary after that bank come for verification of noc that time society come to know that 2nd person sold his flat to 3rd person .society given to bank statement that we are not issue noc for mortgage loan . said flat property tax come with 1 st owner name.share certificate is on 1st owner name . 2nd owner having duplicate stamp of society and many time used it with duplicate chairman and secertary sign for legal purpose that is in reg agreememt also. now how to handle this case pls pls advice me as early as possible .