Container closure

A container having an opening and a closure movable between a first position in which the opening is closed and a second position in which the opening is exposed, the closure comprising a closure flap located within the container and a pivot arm, the pivot arm having a first end secured to the closure flap and a second end having a weighted portion, the pivot arm being pivotally mounted within the container at a pivot point located between the first and second ends, wherein when the container is in a first position, the centre of mass of the weighted portion is offset horizontally and vertically from the pivot point and acts to bias the closure flap to close the opening and when the container is rotated in a first direction to a second position, the weighted portion causes the pivot arm and the closure flap to rotate relative to the container in a second direction opposite to the first direction, thereby to bias the closure flap away from the opening in order to expose the opening, wherein in the first position, the weighted portion is offset vertically by a greater distance than it is offset horizontally.