A locking device includes a lock body, a hasp and a seal. The lock body includes a hasp locking latch pivotally disposed therein and a seal locking latch pivotally disposed therein. The hasp is disposed at the lock body and movable between an open state, where a free end of the hasp is external the lock body, and a closed state, where the free end of the hasp is within the lock body. The seal, when inserted into the lock body when the hasp is in its closed state, engages the hasp locking latch to pivot the hasp locking latch to engage and lock the hasp in its closed state, and the seal, when inserted into the lock body, engages the seal locking latch to lock the seal within the lock body. The seal includes a frangible portion that is configured to break the seal into first and second portions.