Mere possession and recovery of currency notes from an accused without proof of demand would not establish an offence under Sections 7 as well as 13(1)(d)(i)&(ii) of the Act. In the absence of any proof of demand for illegal gratification, the use of corrupt or illegal means or abuse of position as a public servant to obtain any valuable thing or pecuniary advantage cannot be held to be proved. The proof of demand is an indispensable essentiality and of permeating mandate for an offence under Sections 7 and 13 of the Act. Qua Section 20 of the Act, which permits a presumption as envisaged therein, it has been held that while it is extendable only to an offence under Section 7 and not to those under Section 13(1)(d) (i)&(ii) of the Act, it is contingent as well on the proof of acceptance of illegal gratification for doing or forbearing to do any official act. Such proof of acceptance of illegal gratification, it was emphasized, could follow only if there was proof of demand. Axiomatically, in absence of proof of demand, such legal presumption under Section 20 of the Act would also not arise. As a corollary, failure of the prosecution to prove the demand for illegal gratification would be fatal and mere recovery of the amount from the person accused of the offence under Sections 7 or 13 of the Act would not entail his conviction thereunder