Litvinenko murder: German documents find no Russian link
Chaika says Russia's position remains the same as a comprehensive investigation by the Prosecutor General’s Office into the murder found no evidence to link Russia to the case.
German police became involved when Russian businessman Dmitry Kovtun, who lives in Germany, was named as a key witness.
Litvinenko was poisoned in London in November 2006 with Polonium 210, a rare radioactive isotope.
The UK accuses the former Russian security officer, Andrey Lugovoi, of the murder, and wants him extradited to face arrest. Moscow has refused Britain's request to hand over Lugovoi, because it contradicts the Russian constitution.