FBI agents have alleged Vladimir Putin’s former media czar was “beaten to death”, casting doubt on a US government investigation.

Buzzfeed US has reported two FBI agents – as well as a third agent and a serving US intelligence officer – claim Mr Putin’s media executive Mikhail Lesin was bludgeoned to death in 2015 just hours before he was scheduled to meet with the US Justice Department.

“Lesin was beaten to death,” one of the FBI agents told BuzzFeed.

“I would implore you to say as much. There seems to be an effort here to cover up that fact for reasons I can’t get into.”

Last month, Buzzfeed published the results of a two-year investigation into 14 suspicious deaths in the UK, quoting US intelligence officials who linked the deaths to Russian intelligence and the Russian mafia.

However, UK police said at the time that the deaths did not involve “foul play”.

Mr Lesin’s body was discovered in his Dupont Circle hotel room on November 5, 2015, with injuries to his head, neck and torso.

Last October the Department of Justice said police, the US Attorney’s Office and the FBI, had deemed Mr Lesin’s death was an “accident”, noting excessive alcohol consumption as a contributing cause.

The almost year-long investigation was closed based on video footage and witness interviews claiming the 57-year-old had sustained injuries while alone in his hotel room.

A total of 18 former intelligence officials, law enforcement officials and other federal officials, told BuzzFeed they question the “official story of how Mr Lesin died”.

One said there wasn’t a single person inside the FBI who believed “this guy got drunk, fell down, and died”.

“Everyone thinks he was whacked and that Putin or the Kremlin were behind it.”

The FBI agents also alleged the Department of Justice paid for the hotel room where Mr Lesin died.

Department of Justice officials had invited the Russian official to Washington for an interview about RT TV network, formerly known as Russia Today.

The US Attorney’s Office declined to comment on the new allegations beyond their official statement last year that deemed Mr Lesin’s death an accident.

The Buzzfeed report comes the same day the Russian Foreign Ministry seized two American diplomatic properties and ordered the United States Embassy to reduce its staff.

The move was considered to signal Moscow’s frustration towards US President Donald Trump’s failure to improve ties with the Putin administration.

On Friday US time, the White House announced President Trump would sign legislation to impose new sanctions on Russia.

In signing the bill into law, Mr Trump will not be able to ease sanctions against Russia unless he seeks congressional approval.

Curtin University international relations and national security professor Alexey Muraviev told The New Daily Russia’s actions could lead to another spate of confrontational interactions between the two nations.

Dr Muraviev said Russia’s recent actions were a “delayed” response to the Obama administration expelling 35 Russians diplomats in December last year.

He explained the delay had been driven by Mr Trump’s pledge to Mr Putin that the US would rebuild relations between Russia after their meeting at the G20 conference in Hamburg.

“It says, ‘We gave Americans enough time to reconsider their approach’, but Obama and Trump haven’t been able to implement promises, curtailed by inner struggles by the US legislative and judicial branch.”