Tamperproof overcap

In a closure arrangement for a container having a neck with an outwardly projecting annular flange and a plug type closure adapted to be received within said neck, a unitary, molded plastic, tamperproof overcap, comprising:

• (a) a hollow body including a pair of generally similar, semi-cylindrical body sections having corresponding ends joined by integral hinge means;
• (b) said body sections including a detachably removable top wall and a locking ring adapted to snugly engage said container neck flange;
• (c) said locking ring including integral locking means, for interconnecting the free ends thereof, which are readily attachable to each other but which cannot be detached from each other without being destroyed.