A closure for pipeline pig sender or receiver includes a primary closure body and a secondary closure body. The primary closure body has an outer face, an inner face and a port extending therethrough from the outer face to the inner face. The primary closure body is secured to the pipeline pig sender or receiver sealing a closure end when the primary closure body is in the closed position. The secondary closure body closes the port on the primary closure body. The secondary closure body is movable between a closed position and an open position to enable an operator to insert a tool through the port into the diversionary passage to manipulate the pipeline pig and release trapped pressure prior to opening the closure. The secondary closure body is secured to the primary closure body sealing the port when the secondary closure body is in the closed position.