Vladimir Putin should be held responsible for the murder of Alexander Litvinenko, the inquiry into the Russian spy's death was told as six months of hearings came to an end.
Counsel representing the Litvinenko family told the inquiry that it would be "impossible" for such an "assassination" to happen without the approval of the Russian president, described by counsel as a "morally deranged authoritarian".
Mr Litvinenko, 43, died nearly three weeks after drinking tea laced with polonium-210 in London in November 2006.
Police concluded that the fatal dose was probably consumed during a meeting with Dmitri Kovtun and Andrei Lugovoi at a hotel in central London.
Ben Emmerson QC, representing Mr Litvinenko's widow Marina and son Anatoly, told the inquiry: "Vladimir Putin stands accused of this murder on solid and direct evidence - the best evidence that is ever likely to be available in relation to secret and corrupt criminal enterprise in the Kremlin."