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LONDON - Britain gave the all clear on Thursday to one of four aircraft being monitored for radiation in an ever widening probe into the death from poisoning of a former Russian spy that has heightened tensions with Moscow.
But other planes may need to be tracked, Home Secretary John Reid told parliament as he pledged there would be no political barriers to the police investigation.
Reid said police had found radioactive traces at 12 out of 24 locations being checked in connection with the death of Alexander Litvinenko, a former Russian spy who became an outspoken critic of Russian President Vladimir Putin.
Litvinenko accused Putin of ordering his death but the Kremlin and Russia's foreign spy service deny any involvement.
The former KGB agent, who became a British citizen while living in London, died in the capital a week ago after being poisoned with radioactive polonium 210.
British Airways had said "very low traces" of a radioactive substance had been found on two planes being held at London's Heathrow airport.
It said one of the planes had been cleared by health officials on Thursday evening to fly again. The Health Protection Agency said passengers had not been at risk of radiation poisoning.
Officials were now checking the second plane at Heathrow, while a third BA craft in Moscow would be flown back to London on Friday to undergo tests. All three aircraft had travelled between the Russian capital and London.
A fourth plane, a Boeing 737 leased by Russian carrier Transaero that landed at Heathrow on Thursday, was also given the all clear after being checked by police.
"There is one other Russian plane, that we know, that we think we would be interested in," Reid said. "There may be other airplanes of which we don't at this stage know."
The announcement about the planes and their destinations could rekindle suspicions of a Moscow link to the poisoning.
Alex Goldfarb, a close friend of Litvinenko, told reporters in London he suspected the radiation had come from Russia.
"Alexander was convinced Mr Putin was personally involved in this," Goldfarb said as an inquest into Litvinenko's death was opened in London and adjourned.
In Moscow, Anatoly Safonov, Putin's counter-terrorism adviser, told Reuters: "As we said before, we are open and willing to offer all the help needed."
Reid said Moscow had promised cooperation to the "highest level": "There certainly will be no political prohibition on the police following where the evidence leads them."
He added Britain would contact the governments of every country where the planes may have landed.
In a separate development, Russian doctors said they had identified no natural cause for an ailment afflicting former Russian Prime Minister Yegor Gaidar, who fell ill during a trip to Ireland the day after Litvinenko died.
Doctors said it was too early to say whether he had been poisoned, his spokesman Valery Natarov said.
Gaidar, an academic who has voiced restrained criticism of Putin's economic policies, is recovering in a Moscow hospital.
In Britain, some 7500 BA passengers had called a helpline seeking health reassurances after the airline's announcement.
BA says the health risk is low. It faces a huge task tracing 33,000 people who used the planes over a five-week period.
- REUTERS
