Follow Newsnight's continuing investigation into the suspected radiation poisoning of ex-Russian agent Alexander Litvinenko....
Litvinenko dossier uncovered
In his latest report about the poisoned former intelligence agent, Tim Whewell uncovers new evidence of Litvinenko's ability to make powerful enemies.
FIRST BROADCAST: Friday, 9 February, 2007
Litvinenko 'a traitor' claim
"I didn't advise any of them to go and kill Litvinenko, though one of them did say: 'listen - he's done you so much wrong - shall I bring you his head?' " - These are the words of Alexander Gusak of the Russian Secret Service - the one time boss of the poisoned Russian spy Alexander Litvinenko.
He spoke exclusively to our reporter Tim Whewell about Litvinenko's murder. Tim also uncovered astonishing evidence about the way the secret service, known as the FSB, operate.
FIRST BROADCAST: Wednesday, 7 February, 2007
Litvinenko friend Boris Berezovsky interviewed
He's a Russian Oligarch, known as a friend and sponsor of the poisoned former spy Alexander Litvinenko.
Boris Berezovsky gave Newsnight his first British television interview since the death of Mr Litvinenko.
Sir David Frost spoke to him.
FIRST BROADCAST: Monday, 5 February, 2007
Following the polonium trail
The death of Alexander Litvinenko from suspected polonium-210 poisoning sparked a major investigation.
Newsnight's Susan Watts examined the latest evidence and followed the polonium trail across London.
FIRST BROADCAST: Friday, 15 December, 2006
Killing aimed at destabilising' Russia
In an exclusive Newsnight interview Kremlin spokesman Dmitri Peskov called the killing of Alexander Litvinenko in London an attempt to destabilise Russia.
He told Jeremy Paxman the Russian state was not behind the dissident's death.
FIRST BROADCAST: Monday, 11 December, 2006