The speaker of Russia's lower house of parliament is accusing the United States, European Union, United Kingdom, and other groups of killing Russian opposition leader Alexei Navalny.

Speaker Vyacheslav Volodin made a long series of unsubstantiated accusations via social media and messaging app Telegram. 

"Washington and Brussels are to blame for Navalny’s death," Volodin said, according to translations from the Moscow Times. "Who benefits from Navalny’s death today?"

NAVALNY SPOKESPERSON SAYS 'ALEXEI NAVALNY WAS MURDERED'

"All their names are known: from the Secretary General of NATO and the U.S. leadership to [German Chancellor Olaf] Scholz, [British Prime Minister Rishi] Sunak and [Ukrainian President Volodymyr] Zelensky — they’re the perpetrators of Navalny’s death," he added, according to the Moscow Times.

Navalny was being held at the IK-3 penal colony, also known as "Polar Wolf," in Kharp, which is considered one of the country's toughest prisons.

The country's prison agency announced Friday that the prominent critic of Russian President Vladimir Putin died suddenly in prison at the age of 47.

BIDEN, AFTER NAVALNY'S DEATH, SAYS 'NO DOUBT' THAT 'PUTIN AND HIS THUGS' WERE BEHIND IT

The Federal Prison Service said in a statement that Navalny felt unwell after a walk on Friday and lost consciousness, according to The Associated Press. An ambulance arrived to try to rehabilitate him, but he died, the statement added.

"It is [Washington and Brussels] who made a huge number of ill-fated decisions and cling to their positions who benefit from his death," Volodin claimed.

World leaders and analysts around the world have pointed a finger at Putin's regime as the most obvious suspect in his greatest political opponent's death. 

Putin has tried to kill Navalny in the past via a clandestine operation poisoning him — but the dosage ultimately did not prove fatal and he survived.

President Biden told reporters at the White House Friday that "we don't know exactly what happened, but there is no doubt that the death of Navalny was a consequence of something that Putin and his thugs did."

Secretary of State Antony Blinken said Navalny's "death in a Russian prison and the fixation and fear of one man only underscores the weakness and rot at the heart of the system that Putin has built."

Fox News Digital's Greg Norman contributed to this report.