Abstract: The invention provides a container for a sample comprising a hollow body having a base, a side wall and an open end opposite the base, a closure for that body, the closure being arranged to fit to the body to close the open end thereof; and locking means for locking the closure to the body, in such fashion that the contents of the container cannot be removed without it being apparent on subsequent observation of the container. Preferably said closure is provided with a tear-off portion defined thereon by a line of weakness in the material of the closure, removal of the tear-off portion by tearing along said line of weakness allowing removal of the sample from the body.

Abstract: A re-usable envelope having a zip closure which can be locked closed by a sealing device. The sealing device is of plastics material, one part being mounted to the envelope and the other part being engageable therewith, the sealing device only being operable by breaking said other part. The zip tag includes a part for manual engagement to facilitate closing of the sealing device.

Abstract: A sealing device for reusable envelopes in which a zip is held closed by a breakable plastic seal, the disposable, breakable part of the seal being broken by rotation of a coin in a slot provided.