An extraordinary story has emerged which casts the poisoned spy Alexander Litvinenko as a would-be blackmailer.
Julia Svetlichnaja, a Russian-born politics student, has told The Observer newspaper that he was short of money and that powerful people, including corrupt Kremlin officials, would pay £10,000 each to stop him releasing damaging information.
Ms Svetlichnaja, from the University of Westminster, says Mr Litvinenko had documents from the FSB, the successor to the KGB, containing sensitive details about big business interests.
This is yet another twist in the increasingly complicated investigation into the poisoning of Mr Litvinenko.
Four people in Greece are being tested for radiation exposure after staying at the London hotel visited by Mr Litvinenko. Blood and urine tests have been carried out on the four, who have not been named, for possible polonium-210 contamination.
Officials were alerted when it emerged that the group stayed at the Millennium Hotel in Grosvenor Square, where the former KGB officer met contacts on the day he fell ill.
Yesterday, Russian authorities also grounded a flight that was to take 70 passengers from Moscow's Sheremetyevo airport to Helsinki after traces of radiation were found on board. The Finnair Airbus was later given the all clear when investigators identified the source as a low-level cargo shipment already authorised by the airline.
Officers from Scotland Yard's anti-terrorist branch and the Health Protection Agency (HPA) also conducted a search of Arsenal's Emirates stadium in north London, where a Moscow team recently played.
Officials attempted to reassure football fans by issuing a statement saying that no radiation had been found and there was no risk to public health.
Traces of radiation have been discovered at 12 locations, including a hotel in Sussex and on at least two British Airways planes travelling between Moscow and London. In total, 24 locations have been checked.
Radiation experts at the HPA are confident that the risk of contamination to air passengers is almost non-existent or "trivial". It is understood that they have based this assessment on a computer-generated analysis of the harm posed to a child sucking on a plane armrest.
Tests have also confirmed that Mario Scaramella, who met Mr Litvinenko shortly before he started showing symptoms of poisoning, has a " significant" quantity of polonium-210 in his body but not enough to endanger his life or have any immediate effect on his health.
Doctors at University College Hospital, London, said yesterday that preliminary tests had found "no evidence of radiation toxicity", but said they are continuing to monitor Mr Scaramella's condition. Further tests are expected.Reuse content