A tamper responsive sensor comprising: a carrier printed circuit board (“carrier PCB”), holding a mesh of one or more electrically conductive tracks, a pressure or force sensitive switch contact arranged on top of the carrier PCB and having first and second electrical contact connections, tamper detecting circuitry arranged at the carrier PCB and being powered via two electrical power lines and connected to one or more electrically conductive signal lines, wherein one of said power lines or one of said signal lines is electrically connected to the tamper detecting circuitry via a first tamper line holding the switch contact, and wherein one of said power lines or one of said signal lines is electrically connected to the tamper detecting circuitry via a second tamper line holding a conductive track of the carrier PCB mesh.