Alexei Navalny's mother says she has seen the Russian opposition activist's body

The mother of Russian opposition figure, Alexei Navalny, on Thursday released a video stating that she had been given access to her son’s body in a morgue but that her lawyer had not been able to accompany her.

Lyudmila Navalnya, who has been attempting to retrieve Navalny's corpse since Saturday, also said that investigators claimed to know the cause her son's death but were "blackmailing" her by telling her that if she didn't agree to a secret funeral they would "do something with the body."

NBC News cannot confirm Navalnaya's claims. Russian officials were not immediately available for comment.

Russian authorities reported that Navalny, who had fought a yearslong struggle against official corruption and President Vladimir Putin’s government that saw him survive poisoning attempts, died while in custody at a Siberian prison on Friday.

Prior to today, Russian authorities have said the cause of Navalny’s death is unknown and had previously refused to release his body pending a preliminary inquest.

In a series of Telegram posts, Ivan Zhdanov, an ally of Alexei Navalny and director of the Anti-Corruption Fund, commented on the circumstances of the release, calling it "low and vile."

"Since last night it has been a complete mockery over Alexei’s mother. They took her alone and did not allow the lawyers to be near her," Zhdanov said. "They openly threatened that they would 'turn on their media resources' against her."