Three British Airways aircraft that fly the London-Moscow route are being tested for radiation traces. Of the two in London, traces of radiation have been detected.
Is this how the polonium that killed Russian ex-spy Alexander Litvinenko got into Britain?
An excerpt from the BBC story:
The Boeing 767s, plus a third in Moscow, are being tested as part of the probe into the death in London of former KGB agent Alexander Litvinenko.
BA is contacting passengers who travelled on the 120 European flights affected, including the London to Moscow route.
The airline said it had been advised the risk to public health was low.
BA told the BBC's Moscow bureau the third plane was currently at the city's Domodedovo airport.
A team of British experts - thought to be police experts - will go to Moscow shortly to test the plane.
The airline said it had not been confirmed when the planes could have been contaminated but forensics experts were "looking back to the end of October".
The BBC's Richard Galpin said the traces could be there from anyone who had been in contact with Mr Litvinenko, or could have come from someone bringing the substance to the UK.
Initial results of the forensic tests had shown very low traces of a radioactive substance onboard two of the three aircraft, said BA.
