Britanske vlasti su otpočele istragu i do kraja novembra su se tragovi radijacije od polonijuma 210 pojavili na desetak mjesta, uključujući hotel Millennium, britansku ambasadu u Moskvi i dva aviona British Airwaysa kojima je Lugovoi letio između Londona i Moskve 25. i 31. oktobra.
British authorities launched an investigation and by the end of November traces of polonium 210 radiation turned up in a dozen places, including the Millennium Hotel, the British Embassy in Moscow and two British Airways planes that flew Lugovoi between London and Moscow on October 25th and 31st.