A sealing apparatus for tamper-evidently closing an opening in a sealable product, wherein the opening is closable by means of a fastener, said fastener having a fastener head, wherein the sealing apparatus comprises: a locking housing (12, 14) the housing mountable adjacent said opening and including an entrance passage leading to a stall, the entrance passage having cavities extending laterally therefrom, the fastener head passing in use through said entrance passage into said stall, and further including housing openings in the base of the cavities providing a passage through to a channel comprising a chamber and an exit passage; an actuator tab configured to be attached to and movable about said fastener head to, with said fastener head received into said stall, engage with and close said entrance passage behind said fastener head, said actuator tab further comprising tab openings, wherein, with the actuator tab received in the entrance passage and cavities, the tab openings align with corresponding housing openings in the base of the cavities, providing a passage from the top of the tab through to the chamber in the housing; and a seal comprising a first portion (63, 64) frangibly connected with at least one second portion for tamper-evidently securing said actuator tab in position in said entrance passage, wherein said at least one second portion of said seal comprises at least one leg extending orthogonally from said first portion which is extendable through at least one of said tab openings and the corresponding housing opening and, on breaking at the frangible connection, the at least one leg is adapted to pass into said chamber of said channel and out of said housing through said exit passage. a locking housing (12, 14) the housing mountable adjacent said opening and including an entrance passage leading to a stall, the entrance passage having cavities extending laterally therefrom, the fastener head passing in use through said entrance passage into said stall, and further including housing openings in the base of the cavities providing a passage through to a channel comprising a chamber and an exit passage; the housing mountable adjacent said opening and including an entrance passage leading to a stall, the entrance passage having cavities extending laterally therefrom, the fastener head passing in use through said entrance passage into said stall, and further including housing openings in the base of the cavities providing a passage through to a channel comprising a chamber and an exit passage; an actuator tab configured to be attached to and movable about said fastener head to, with said fastener head received into said stall, engage with and close said entrance passage behind said fastener head, said actuator tab further comprising tab openings, wherein, with the actuator tab received in the entrance passage and cavities, the tab openings align with corresponding housing openings in the base of the cavities, providing a passage from the top of the tab through to the chamber in the housing; and a seal comprising a first portion (63, 64) frangibly connected with at least one second portion for tamper-evidently securing said actuator tab in position in said entrance passage, wherein said at least one second portion of said seal comprises at least one leg extending orthogonally from said first portion which is extendable through at least one of said tab openings and the corresponding housing opening and, on breaking at the frangible connection, the at least one leg is adapted to pass into said chamber of said channel and out of said housing through said exit passage.