Judge Timothy Workman delivered a scathing indictment of Russia’s criminal justice system, ruling that the extradition request was politically motivated, meaning Mr Zakayev is free to remain in Britain.
“I have come to the inevitable conclusion that if the (Russian) authorities are prepared to resort to torturing witnesses, there is a substantial risk that Mr Zakayev would himself be subject to torture.”
Russia had sought to extradite Mr Zakayev on 13 charges including murder and kidnapping.
The charges date from the first of two wars in the breakaway region from 1994-96, but in the years since Mr Zakayev became the chief Chechen peace negotiator, meeting Russian officials in Moscow as recently as 2001.
But he was arrested in December 2002 at London’s Heathrow airport after arriving from Denmark. Moscow had also tried to extradite unsuccessfully to extradite him from Denmark.
Mr Zakayev and his supporters said the court decision recognised that Russian authorities are committing human rights abuses against Chechens.
Amnesty International has called for an inquiry after allegations from one of the witness who said he was tortured into providing accounts to support Russia’s extradition bid.
However the Kremlin reacted angrily, saying the decision will undermine bilateral relations and the global “war on terrorism”.
It accused London of “double standards” and said the move “contradicts the very basis of international cooperation in the fighting against terror”.
British actress and human rights activist Vanessa Redgrave, who supported Mr Zakayev’s fight against extradition, said: “It is the greatest victory for the Chechen people and for Akhmed Zakayev and for all the Russian people who fought for the truth of the situation.”