Alexander Litvinenko may have survived two previous attempts on his life before he was assassinated, it has been reported.
The former Russian spy, a fierce critic of the Kremlin, was killed on the third attempt, according to the BBC.
Litvinenko was poisoned in November 2006 during a meeting at a Mayfair hotel with two former Russian agents. He died three weeks later. Tests revealed that he ingested a rare isotope, polonium 210, which is hard to detect.
A public inquiry into the murder was to open today. The hearings, many of which will be held in secret, will be carried out over nine weeks in the London High Court.
It is understood that details of two earlier attempts on Litvinenko's life may emerge during the proceedings.
