Russian opposition leader Alexei Navalny's funeral is planned for Friday in a Moscow church, his allies said two weeks after his shock death in an Arctic prison.

Authorities resisted handing Navalny's body to his family for eight days, in what his team said was an attempt to "cover" up who was responsible for his death and prevent a public burial.

His widow Yulia Navalnaya said she feared her husband's funeral could be disrupted by arrests.

"I'm not sure yet whether it will be peaceful or whether the police will arrest those who have come to say goodbye to my husband," Navalnaya told the European Parliament. 

The burial is set to take place at the nearby Borisov cemetery, a short walk from the banks of the river Moskva.

"Alexei's funeral will be held at the 'Mother of God Quench My Sorrows' church in Maryino on 1 March at 14:00 (1100 GMT). Come in advance," his team said in a social media post on Wednesday.

Finding a church willing to host the service was difficult, his team said, as the Kremlin was afraid a public funeral could turn into a show of support for Navalny's movement.

"We started to look for a church and a hall for 1 March. Everywhere they refused to give us anything. In some places we were told it was forbidden," said exiled ally Ivan Zhdanov.

"We don't care about the message. Alexei needs to be buried... To have a chance to say goodbye, it is better to come in advance," he added.

Navalny spokeswoman Kira Yarmysh said they began looking for a funeral location this week, a few days after his body was finally handed to his mother Lyudmila Navalnaya.

"Some of them say the place is fully booked. Some refuse when we mention the surname Navalny. In one place, we were told that the funeral agencies were forbidden to work with us," Yarmysh said.

- Dozens detained -

Russian authorities said Navalny died of "natural causes" after he lost consciousness following a walk in his prison colony, nicknamed "Polar Wolf".

His team and Western leaders have cast doubt on this assertion, alleging that Putin was directly responsible for his death.

Details of the funeral and how many mourners will be allowed to attend are unclear, and there was no immediate response from Russian officials.

Authorities had threatened to bury him on the prison grounds where he died unless his family agreed to a private ceremony, his team previously said.

Putin, who famously never referred to the opposition leader by name, has so far remained silent on Navalny's death.

Authorities have cracked down on public gatherings in memory of Navalny, detaining hundreds for laying flowers at memorials and other acts of protest.

Dozens have already been handed prison sentences, including 154 in Saint Petersburg alone.

The opposition leader shot to prominence through his anti-corruption campaigning, exposing what he said was rampant corruption at the top of Putin's administration.

He was arrested in January 2021 when he returned to Russia after being treated in Germany for a poisoning attack he suffered while campaigning against Putin in Siberia months earlier.