The first attempt to synthesise seaborgium in cold fusion reactions was performed in September 1974 by a Soviet team led by G. N. Flerov at the Joint Institute for Nuclear Research at Dubna. They reported producing a 0.48 s spontaneous fission (SF) activity, which they assigned to the isotope 259Sg. Based on later evidence it was suggested that the team most likely measured the decay of 260Sg and its daughter 256Rf. The TWG concluded that, at the time, the results were insufficiently convincing.