I bought a property from a registered POA holder during 2007, the POA in 1982 has got GPA from a land owner for development of flats, the POA CUM builder has agreed to develop some portion of independent house to principal and handed over to the house,remaining portion he developed flats and sold to public then paid all the amount to them .POA has done sale agreement (unregistered) with land owner that for develop the flats he wants to keep 1 flats which was unapporoved ,during 1985 land owner family has left that place by selling his independent house , now the POA does not know whereabouts of principal family, the only document he has is the orginal GPA document duly registered, till 2007 POA has not registred this property in his name and flats were assessed municipal taxes in builders name from 1987 to 2006, during 2006 POA transfered through settlement deed to his son subsequently his son sold the flat to me .Is this transaction is legal?