We show that existing laboratory experiments have the potential to unveil the origin of matter in the universe by probing leptogenesis in the pure type-I seesaw model with three right-handed neutrinos and Majorana masses in the GeV range. The baryon asymmetry is generated by CP-violating flavour oscillations during the production of the right handed neutrinos. In contrast to the case with only two right handed neutrinos, no degeneracy in the Majorana masses is required. The right handed neutrinos can be found in meson decays at LHCb or BELLE II.