Why was Alexander Litvinenko murdered?

The following excerpt is from an interview with Akhmed Zakayev (AZ), December 5, 2006, conducted by Frankfurter Allgemeine Sonntagszeitung (FAZ).

FAZ: Do you see a connection between the murder and the two laws passed by the Duma in July, about the “liquidation” of people opposing the regime?

AZ: Of course. And because of this, the Europeans shouldn’t pretend that this murder wasn’t to be expected. The Duma passed two laws in July, on the eve of the G8 summit in St. Petersburg. The first one allows the government to liquidate “extremists” and “terrorist” abroad. The second one defines people opposing the government and regime critics as extremists.