A container comprising a lid comprising a central portion and a circumferential rim, the rim comprising an aperture at least at one location around a perimeter of the rim; and a body comprising a base and lateral walls extending up from the base and ending up in a rim, the rim comprising a knob at least at one location thereof; wherein, in a closed position of the lid over the body, the knob is received in the aperture and is seen emerging from the aperture, and, upon lifting the lid up from the closed position for the first time, the knob disengages from the aperture, thus deforming at least one of the aperture and the rim of the lid, the deformed part testifying of a first opening of the container.