Plug with tamper evident seal

A stopper (1) for a container has a cover part (2) which is connected to a peripheral wall (3) encompassing the edge of the container opening, and a ring (4) formed onto the cover part for clamping engagement in the container opening. A tear-off ring (6) is connected via a plurality of circumferentially spaced attachment webs (5) to the peripheral wall (3). Between the attachment webs, wedge-shaped projections (7) are formed on the tear-off ring, which projections overhang an external, inversely wedge-shaped, circumferential projection of the container in the mounting position for securing the authenticity of the container contents. The tear-off ring (6) has, proceeding from its free edge, a cut (11) which separates the wall of the tear-off ring at least over a portion of its width, so that the tear-off ring can be engaged underneath at the cut as a tear-off tab.