The secret cross border tracking of persons or vehicles by placing a beeper, is admissible in order to clear up a punishable act or to determine the whereabouts of an accused person and only in case of a suspicion of a punishable act committed with intent, that carries a prison term of more than one year and where it is to be expected, on account of certain facts, that the person observed has committed the crime or will establish contact with the accused or that the whereabouts of a fugitive or absent accused may be determined.
The use of technical means which, by means of the transmission of signals, make it possible to determine the spatial area in which the person under surveillance is located and the opening of vehicles and containers for the purpose of inserting such technical means is permissible in order to support the observation, provided that the observation would otherwise be futile or substantially impeded.