Former Russian Press Minister Mikhail Lesin, who was found dead in a Washington hotel room last year, died of blunt force injuries to the head, U.S. authorities said on Thursday.

Lesin who once headed the state-controlled Gazprom Media, also had blunt force injuries to the neck, torso, arms and legs, the U.S. capital's Office of the Chief Medical Examiner and the Metropolitan Police Department said in a brief statement.

According to a police incident report, Lesin, who was President Vladimir Putin's press minister from 1999 to 2004, was found unconscious on Nov. 5 on the floor of his room in the Doyle Washington Hotel. The hotel is also known as the Dupont Circle Hotel.

An ambulance was called and he was pronounced dead at the scene.

Russia's RT television quoted family members at the time as saying he had died of a heart attack.

A U.S. law enforcement source said on Thursday the investigation into Lesin's death was being led by Washington, D.C. police.

The investigation was focused on Lesin's death, but that did not rule out a possible change to a murder probe, said the source, who declined to be identified when discussing the matter.

The source said when police first investigated the hotel room where Lesin's body was found, they did not find any damage or evidence indicating foul play.

A spokesman for the Russian Embassy in the United States said their officials for the past several months have requested through diplomatic channels information regarding the progress of the investigation.

"No substantial information has been provided. With regard to the document that has been released to the public today, we expect the American side to provide us with relevant official explanation," press secretary Yury Melnik said in an email.

ABC News has said Lesin had been accused of censoring Russia's independent media. He became head of Gazprom-Media Holding in 2013 but resigned the following year.