Tamper evident closure device

A tamper evident closure device comprises a screw-threaded inner cap member 10 and outer cap member 14, which rotates freely in the unscrewing direction without engagement of the inner cap and has an aperture, covered by a tamper evident tear strip 27 which must be removed or destroyed to permit unscrewing of the closure as a whole unit. The inner and outer cap mutually engage, either by insertion of a tool into a slot in the upper surface of the inner cap or by depression of the outer cap, for unscrewing of the closure. The tear strip may be a self adhesive label which may comprise a projecting tab which can be removed to fully expose a portion of the inner cap member. The label may comprise a main portion and a removable portion over the aperture with lines of weakness between the two, may be free of adhesive, may be circular and adhered concentrically on the outer cap member, and may carry opening instructions and/or a hologram. The inner and outer cap members may be of different colours. Fingers 22 on an inside top surface of the outer cap and dogs 23 on the top of the inner cap engage to allow the cap to be screwed on, and slip in the opposite direction to prevent unscrewing. In a separate embodiment, a one piece moulded closure cap has a depending cylindrical skirt (12, fig.3) and a resilient flexible annular seal (30, fig.3) on the internal surface of the top of the cap.