Activation of the surrounding of an accelerator must be quantified and those data provided to the official agencies. This is a necessary step in obtaining the appropriate authorization to operate such accelerator. The SwissFEL, being a 4^th generation light source, will produce more accelerated charges, which are dumped or lost, than any conventional 3^rd generation light source, like the Swiss Light Source. We have simulated the propagation of a dark current beam produced in the photoelectron gun using tracking codes like ASTRA and Elegant for the current layout of the SwissFEL. Detailed experimental study have been carried out at the SwissFEL test facilities at PSI (C-Band RF Stand and SwissFEL Injector Test Facility), in order to provide necessary input data for detailed study of components using the simulation code OPAL. A summary of these studies are presented.