A system for detecting a presence in an environment to be monitored includes an electrostatic charge variation sensor, a vibration sensor, and an environmental pressure sensor. A processing unit is configured to acquire, from the electrostatic charge variation sensor, an electrostatic charge variation signal, and detect in the electrostatic charge variation signal, first signal characteristics indicative of the presence of a subject in the environment to be monitored. The processing unit further validates the detection of presence of the subject using the vibration and pressure signals provided by the other sensors.