Container with tamper-evident and pre-lockable closure assembly

A container, comprising:

• a main body having a top provided with a fill stub (28) which is formed with threads and protrusions (32);
• a screw cap (12) having complementary threads;
• and
• an index ring (14) serving as an authenticity seal and attached to the screw cap via thin connecting webs (16), said index ring having flexible locking members (34) to engage nondetachably behind the protrusions (32) such that the connecting webs (16) acting as predetermined breaking points, are severed when the screw cap is released from a fully closed position in which the container is sealed by the screw cap,
• said fill stub being provided with at least one cam (36) for a preliminary engagement of the screw cap on the fill stub (28) by at least one of the locking members (34) when the container is still empty and the screw cap has not yet reached the fully closed position, thereby preventing a spontaneous unscrewing and release of the screw cap (12) while still allowing the screw cap (12) to be released for filling the container by overcoming a certain holding force between the at least one cam and the at least one of the locking members (34), the preliminary engagement of the screw cap on the fill stub by the at least one cam and the at least one of the locking members occurring before the locking members nondetachably engage behind the protrusions (32) to seal the filled container.