Alexander Litvinenko

The widow of former Russian spy Alexander Litvinenko has accused Russian President Vladimir Putin of stalling a British inquiry into her husband's murder, and turning the prime suspect into a hero.

A year to the day after Litvinenko was poisoned with radioactive polonium-210, Marina Litvinenko accused Mr. Putin of obstructing the probe.

Shortly before her statement was released Thursday in London, Britain's chief suspect in the murder, former KGB officer Andrei Lugovoi, again denied any involvement in Litvinenko's death. In Moscow, he said he has been victimized by British lies about his involvement.

British prosecutors announced earlier this year that they wanted to charge Lugovoi with murder. But Russian authorities refused to send the suspect to London for trial. Mr. Putin argued that the Russian constitution prohibits such extraditions.

Lugovoi is currently campaigning for a seat in Russia's parliament.

Russia's refusal to extradite Lugovoi plunged British-Russian relations to a post-Cold War low, with each government expelling four diplomats.

Litvinenko died in a London hospital three weeks after first falling ill exactly a year ago. In a deathbed statement, he accused the Russian president of ordering his poisoning. The Kremlin has denied the charge.