A security door system (100, 200) which comprises: a door including: a door frame (102, 202) comprising elongate door frame members (103A-D, 203A-D) each having a first holding channel formed therein and a clamping portion; and a mesh (104, 204) covering an opening enclosed by the door frame (102, 202); and a wall frame (110, 210) comprising elongate wall frame members (111A-D, 211A-D) operably coupled to the door frame (102, 202) 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 (110, 210); 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 (102a, 202a) toward the medial surface (110d, 210d) or vice versa, the anti-lift element (135A-F, 235A-F) extending therefrom to reside adjacent respective medial (110d, 210d) and/or lateral surfaces (102a, 202a) 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 (102, 202) or wall frame (110, 210) upon levering of the door relative to the wall frame (110, 210), and another of the plurality of security members comprise a lip portion (170, 270) disposed laterally from an outer edge portion of the door frame (102, 202) and extending at least partly therearound so as to overlie and abut a portion of an outer surface of the wall frame (110, 210) when in the closed position, the lip portion (170, 270) further comprising a base (171, 271) that tapers as it extends from the door frame (102, 202) outwardly to define a free end. a door including: a door frame (102, 202) comprising elongate door frame members (103A-D, 203A-D) each having a first holding channel formed therein and a clamping portion; and a mesh (104, 204) covering an opening enclosed by the door frame (102, 202); and a wall frame (110, 210) comprising elongate wall frame members (111A-D, 211A-D) operably coupled to the door frame (102, 202) 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 (110, 210); 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 (102a, 202a) toward the medial surface (110d, 210d) or vice versa, the anti-lift element (135A-F, 235A-F) extending therefrom to reside adjacent respective medial (110d, 210d) and/or lateral surfaces (102a, 202a) 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 (102, 202) or wall frame (110, 210) upon levering of the door relative to the wall frame (110, 210), and another of the plurality of security members comprise a lip portion (170, 270) disposed laterally from an outer edge portion of the door frame (102, 202) and extending at least partly therearound so as to overlie and abut a portion of an outer surface of the wall frame (110, 210) when in the closed position, the lip portion (170, 270) further comprising a base (171, 271) that tapers as it extends from the door frame (102, 202) outwardly to define a free end.