Putin said British officials should have known that Russia's constitution would prevent the extradition.

"From whatever side you look at this problem, there's one stupidity," Putin said in an interview with journalists from Group of Eight countries ahead of this week's G-8 summit in Germany.

"If they didn't know (about the constitutional prohibition) it's a low level of competence and thus we have doubts about what they're doing there," Putin said, according to a transcript released by the Kremlin. "And if they knew and did this, it's simply politics.

- Putin: UK calls for Lugovoi 'stupidity'

Kick the Russians out - comments, as always, are the best.