Under sub-rule 3 of Rule 15 of the Central Civil Service (Conduct) Rules, 1955 (now Rule 18 of 1964 Rules) every member of Class I (Group A) and Class II (Group B) services shall, on first appointment to Government service and thereafter at intervals of 12 months, submit a return of immovable property owned, acquired or inherited by him or held by him on lease or mortgage, either in his own name or in the name of any member of his family or in the name of any other person.