A security door system which comprises: a door including: a door frame comprising elongate door frame members (103A-D, 203A-D) each having a first holding channel formed therein and a clamping portion; and a mesh covering an opening enclosed by the door frame ; and a wall frame comprising elongate wall frame members (111A-D, 211A-D) operably coupled to the door frame by one or more hinge members (130A-C, 230A-C), the hinge members (130A-C, 230A-C) facilitating pivotable movement of the door between open and closed positions; and a plurality of security members configured to prevent or inhibit levering of the door relative to the wall frame ; characterised in that one of the plurality of security members comprise an anti-lift element (135A-F, 235A-F) disposed in or on a lateral surface of one or more of the door frame members (103A-D, 203A-D) and/or a medial surface of one or more of the wall frame members (111A-D, 211A-D), the anti-lift element (135A-F, 235A-F) extending in the plane of the door from the lateral surface toward the medial surface or vice versa, the anti-lift element (135A-F, 235A-F) extending therefrom to reside adjacent respective medial and/or lateral surfaces of an opposed wall frame member (111A, C; 211A, C) and/or door frame member (103A, C; 203A, C) when the door is in the closed position, the anti-lift element (135A-F, 235A-F) adapted to contact the door frame or wall frame upon levering of the door relative to the wall frame , and another of the plurality of security members comprise a lip portion disposed laterally from an outer edge portion of the door frame and extending at least partly therearound so as to overlie and abut a portion of an outer surface of the wall frame when in the closed position, the lip portion further comprising a base that tapers as it extends from the door frame outwardly to define a free end. a door including: a door frame comprising elongate door frame members (103A-D, 203A-D) each having a first holding channel formed therein and a clamping portion; and a mesh covering an opening enclosed by the door frame ; and a wall frame comprising elongate wall frame members (111A-D, 211A-D) operably coupled to the door frame by one or more hinge members (130A-C, 230A-C), the hinge members (130A-C, 230A-C) facilitating pivotable movement of the door between open and closed positions; and a plurality of security members configured to prevent or inhibit levering of the door relative to the wall frame ; characterised in that one of the plurality of security members comprise an anti-lift element (135A-F, 235A-F) disposed in or on a lateral surface of one or more of the door frame members (103A-D, 203A-D) and/or a medial surface of one or more of the wall frame members (111A-D, 211A-D), the anti-lift element (135A-F, 235A-F) extending in the plane of the door from the lateral surface toward the medial surface or vice versa, the anti-lift element (135A-F, 235A-F) extending therefrom to reside adjacent respective medial and/or lateral surfaces of an opposed wall frame member (111A, C; 211A, C) and/or door frame member (103A, C; 203A, C) when the door is in the closed position, the anti-lift element (135A-F, 235A-F) adapted to contact the door frame or wall frame upon levering of the door relative to the wall frame , and another of the plurality of security members comprise a lip portion disposed laterally from an outer edge portion of the door frame and extending at least partly therearound so as to overlie and abut a portion of an outer surface of the wall frame when in the closed position, the lip portion further comprising a base that tapers as it extends from the door frame outwardly to define a free end. <EOS>