London, Nov.24 : The father of murdered ex-KGB spy Alexander Litvinenko has described Russian President Vladimir Putin was his son's chief executioner.

Exactly a year after Litvinenko's death,  dad Walter, 79, said in London:

"Main executioner Mr Putin wants to maintain power to cover his crime."

Litvinenko's widow Marina confirmed the family was taking the case to the European Court of Human Rights.

She said Putin was protecting suspect Andrei Lugovoi, 42, "tainting his office". (ANI)