Alexei Navalny's funeral service and burial will take place in Moscow on Friday, his spokesperson confirmed on Wednesday.
Kira Yarmysh posted on X that a service for the Russian opposition leader would be held on Friday at 2pm Moscow time (11am GMT) in the Church of the Icon of the Mother of God in the district of Maryino.
She told people to get there early, before Mr Navalny is buried at the Borisovskoye cemetery.
The 47-year-old died at an Arctic penal colony on February 16, while serving a 19-year sentence on charges widely seen as politically motivated.
His allies have accused President Vladimir Putin of having him murdered ahead of a potential prisoner swap.
The Kremlin, which casts Mr Navalny and his supporters as US-backed extremists, has denied state involvement in his death and said it is unaware of any agreement to free Mr Navalny prior to his death.
It comes after an associate claimed that talks to free Mr Navalny in a prisoner swap were in their “final stages” when he died.Mr Navalny's death certificate reportedly states that he died of natural causes.
His mother Lyudmila Navalnaya accused authorities of trying to blackmail her into holding a private funeral for her son by initially withholding his body, an assertion the Kremlin called absurd.
Mr Navalny's allies had been looking for a hall to accommodate his supporters at a farewell ceremony, but said on Tuesday they had been refused everywhere.
Ms Yarmysh said one venue had told them that “funeral agencies were prohibited from working with us".
Ivan Zhdanov, the director of Navalny's Anti-Corruption Foundation, said the funeral was initially planned for Thursday - the day of Putin's annual address to Russia's Federal Assembly - but no venue would agree to hold it then.
"The real reason is clear. The Kremlin understands that nobody will need Putin and his message on the day we say farewell to Alexei," he wrote on Telegram.
On the same day, Mr Navalny's lawyer Vasily Dubkov was briefly detained and in Moscow - after helping Ms Navalnaya recover her son’s body.
Mr Dubkov later told independent news outlet Verstka that he had been released, but did not comment on the reason for his detention.
