Abstract: The embodiments herein relate to a system and method for detecting an internal object in a body under test. The system comprises at least one antenna which are adapted to be positioned around the body under test. The system is adapted to transmit radio frequency signal(s) into the body under test which are reflected and/or scattered from the internal object. The system is adapted to receive the reflected and/or scattered radio frequency signal(s) and use a method of classification S1-S7 to determine the presence of an internal object. The system is adapted to detect the internal object or a change in an already detected internal object when there is a difference between the received radio frequency signals. The difference is related to the different dielectric properties between the internal object and the body under test.