Sir Robert Owen, leading the inquiry into spy’s death, says that Dmitry Kovtun either never intended to give evidence or ‘obstacles were put in his way’Claims by a suspect in the killing of Alexander Litvinenko that he wanted to give evidence to the inquiry into the spy’s death may have been a “charade”, the judge leading the probe has said.Dmitry Kovtun was due to provide testimony by video link from Moscow but withdrew at the 11th hour.