US authorities have announced that Mikhail Lesin, a long-time aide to Russian President Vladimir Putin, died as the result of a blow to the head.

Lesin, who also served as Russia's Communications Minister from 1999 to 2004, was found unconscious in a Washington apartment last November. At first, his family members claimed that he had died of a heart attack.

The US conducted an autopsy on Lesin,which revealed his violent demise. It is not known how he received the strike or who administered it to him.