Ex-Putin aide died in US hotel of blunt force injuries to the head: official
Mikhail Lesin, who helped launch the Russian English-language television network RT, was found dead in a Washington hotel in November at the age of 57 (AFP Photo/Alexander Nemenov)

A former aide to Russian President Vladimir Putin found dead in a Washington hotel suffered blunt force injuries to the head, not a heart attack as initially claimed, the US capital's chief medical examiner said.

Mikhail Lesin, 57, a former press minister accused of curtailing media freedoms in Putin's Russia, also suffered injuries to his neck, torso and upper and lower extremities, the chief medical examiner said.

Putin's spokesman said in response Friday that the Kremlin expected the United States to provide "detailed official information" about Lesin's murky death on November 5.

The official findings -- made public more than four months after his death -- contradict previous Russian state media reports, citing his family, that said Lesin died of a heart attack.

They also would appear to indicate that he was killed.

The New York Times said Lesin's injuries were the result of "some sort of altercation" that took place before he returned to the Dupont Circle Hotel where he was staying.

Lesin's sudden death triggered a host of conspiracy theories in Russia, but Washington police cautioned it was too early to jump to conclusions and stressed that the medical examiner had concluded that the manner of death was "undetermined."

"We cannot definitively state that foul play was a factor as that would be speculation at this point in the investigation," said police spokesman Dustin Sternbeck, adding that the investigation was ongoing.

Lesin helped launch the Russian English-language television network RT and allegedly amassed millions of dollars in assets in Europe and the United States while working for the government, including $28 million in real estate in Los Angeles.

Moscow, whose relations with Washington have plummeted over Ukraine and Syria, voiced irritation at the handling of the case.

"We have not received any detailed information through the channels established to deal with these situations," Putin spokesman Dmitry Peskov told reporters in Moscow.

Maria Zakharova, spokeswoman for the Russian foreign ministry, told AFP that Moscow was still waiting for the US State Department to release information related to Lesin's death.

Russia's Prosecutor General Yury Chaika has sent the United States Department of Justice a request to release documents related to his death, an official from his office was quoted as saying by state news agency RIA Novosti.

Lesin was Russia's minister of press, television and radio between 1999 and 2004, and later served as a Kremlin aide.

In 2013, he became head of Gazprom-Media Holding, the media arm of state energy giant Gazprom, and oversaw Russia's top liberal radio station Echo of Moscow.

Lesin resigned a year later, citing family reasons.

In 2014, Republican Senator Roger Wicker of Mississippi called for a probe into Lesin on suspicion of money laundering and corruption.

"That a Russian public servant could have amassed the considerable funds required to acquire and maintain these assets in Europe and the United States raises serious questions," Wicker wrote.