Russia's chief prosecutor has said he would help British detectives investigate the death by poisoning of former spy Alexander Litvinenko but said that suspects would not be extradited.
Detectives from Scotland Yard have begun their investigation in Moscow into Mr Litvinenko's death in London last month.
A team of experts from Britain will also begin to carry out 'precautionary tests' for radiation at the British Embassy in Moscow today.
However, the detectives will not be allowed to interview a former Russian intelligence officer who was jailed for divulging state secrets.
The Foreign Minister, Sergei Lavrov, has warned that the incident is harming relations between the two countries.
Meanwhile, the former Russian Prime Minister, Yegor Gaidar, has been released from a Moscow hospital where he had been recovering after collapsing at a conference in Maynooth last week.
No radiation has been detected at places in Ireland visited by Mr Gaidar.
