In November 2006 ex KGB agent Alexander Litvinenko was murdered in London. Last week a British inquiry concluded that President Vladimir Putin had probably approved a 2006 Russian intelligence operation to murder Litvinenko using radioactive Polonium-210 in London. The finding prompted a diplomatic row between London and Moscow but as yet has not resulted in any concrete actions.

A month before his death in November 2006 Litvinenko had spoken out at the Frontline Club claiming Putin was responsible for the death of journalist, writer, and human rights activist Anna Politkovskaya known for her opposition to the Second Chechen War and Vladimir Putin.

With this in mind we spoke to Luke Harding, The Guardian’s Moscow correspondent between 2007 and 2011 and author of 'Mafia State: How one reporter became an enemy of the brutal new Russia'. His book entitled 'A Very Expensive Poison' comes out on March the 17th of this year.