Section 24(4)(b) in The Tamil Nadu Agricultural Produce Marketing (Regulation) Act, 1987
(b)The burden of proving that any notified agricultural produce is not liable for the levy of fee or the fee payable has already been paid under this section shall lie on the person claiming such v exemption or non-liability find till it is established with sufficient records to the satisfaction of the market committee that the notified agricultural produce has already suffered the liability, the fee due on such produce shall he paid.