[JURIST] Russia has opened a criminal investigation into the death of former Russian spy Alexander Litvinenko [BBC timeline], the Russian Prosecutor General's office said Thursday. Litvinenko, who once worked for the Russian Security Federal Bureau, was poisoned in London on November 1, and passed away due to radiation poisoning [Reuters report] on November 23. Scotland Yard said Wednesday that it is treating Litvinenko's death as murder [Guardian report]. Officials suspect the poisoning occurred during a lunch meeting between Litvinenko and several Russian businessmen at a London hotel, including Dmitry Kovtun and Andrei Lugovoi, though both men have denied any involvement [Kommersant report] when speaking to British officials. Traces of radiation have also been found in hotel rooms at the London hotel where Litvinenko stayed in October and November, as well as on airplanes that flew into England. Prosecutors also opened a criminal investigation into the attempted murder of Kovtun. The investigation will allow Russia to request extradition of suspects in the poisoning.

Also on Thursday, Russian intelligence veterans group Honor and Dignity [UK Telegraph backgrounder] denied involvement in the poisoning [RIA Novosti report]. Litvinenko, who accused [statement] Russian President Vladimir Putin of orchestrating his poisoning [CNN report], was laid to rest [RIA Novosti report] in a London cemetery on Thursday. AP has more.