An autopsy has found that blunt force trauma to the head was the cause of death for one of Russian President Vladimir Putin's former aides whose body was found in a Washington hotel room.

District of Columbia police spokesman Officer Hugh Carew confirmed the autopsy results for Mikhail Lesin on Thursday. The D.C. Medical Examiner's Office said in a statement that other contributing causes were blunt force injuries of the neck, torso, arms and legs.

The medical examiner found the manner of death to be undetermined. Carew says police continue to investigate Lesin's death. His body was found at the Doyle Dupont Circle Hotel in November.

Russian media had reported that Lesin suffered a heart attack, citing relatives.

Lesin was a media adviser to Putin who helped found the English-language news service Russia Today.