As per section 70 of Model GST Law, goods become liable to confiscation when any person does the following:
supplies any goods in contravention of any of the provisions of this Act or rules made thereunder leading to evasion of tax;
does not account for any goods on which he is liable to pay tax under this Act;
supplies any goods liable to tax under this Act without having applied for the registration;
contravenes any of the provisions of the CGST/SGST Act or rules made thereunder with intent to evade payment of tax.