Abstract: A container comprises a body portion, a lid portion and, mounted on one of the body portion and the lid portion, a locking member. The locking member is movable from an unlocking position to a locking position in which it engages the other of the body portion and the lid portion to hold the lid in engagement with the body portion. The container is provided with a sealing means including a sealing member which extends between the locking member and other of the body portion and the lid portion when the locking member is in its locking position. Movement of the locking member from the locking to the unlocking position is only possible if the sealing member is rendered ineffective for further sealing use.