(Reuters) - Russia will help British detectives in Moscow to investigate the poisoning death of ex-Russian spy Alexander Litvinenko, but it will not extradite any suspects to Britain, the chief prosecutor said on Tuesday.
"We will do everything to provide legal assistance to our colleagues," Prosecutor-General Yuri Chaika told reporters, referring to a Scotland Yard team of detectives probing the case who are now in the Russian capital, reports Trend.
But he set out clear ground rules for cooperation with British counterparts, saying the detectives could not question anyone independently.
"The person who is accused will be convicted by a Russian court," Chaika, speaking at a news conference, added. Asked about suspects being sent to Britain for trial he said: "This will not be possible."
Police to date have neither charged nor identified as a suspect anyone in the Litvinenko case.
Litvinenko, a former officer in Russia's Federal Security Service (FSB) who became an implacable critic of President Vladimir Putin, died in a London hospital on November 23 from radiation poisoning.
In a statement Litvinenko's associates said he wrote on his death-bed, he accused Putin of ordering his assassination -- a charge Putin has dismissed.
That claim and the heavy exposure it has been given in the British media have angered the Kremlin.
Chaika did say his officials would help the British team gain access to Andrei Lugovoy, a Litvinenko associate who is thought to be of major interest to Scotland Yard.
Lugovoi met Litvinenko in London on November 1, the day he fell ill from what later turned out to be a lethal dose of the radioactive substance polonium 210.
Russian media reported on Tuesday Lugovoy might not be available to talk to the British detectives because he is in hospital being checked for radiation contamination.
"If the doctors allow it -- and according to our information he is ill and in hospital right now -- then he will be questioned without fail," Chaika said.
Chaika dismissed speculation that the polonium 210 used to poison Litvinenko had been smuggled into Britain from Russia.
"I think the leak could not have come from here," he told reporters.