Alexei Navalny's body is lying in the district hospital in the northern Siberian town of Salekhard directly on the Arctic Circle, the independent Russian-language newspaper Novaya Gazeta Europe reported on Sunday.
No autopsy had been conducted on the dissident up to Saturday, the anti-government newspaper currently being published from Latvia reported.
Navalny's unexpected death at the age of 47 in the Polar Wolf penal colony, which was reported two days ago, has generated international outrage.
Novaya Gazeta said its informant, an anonymous emergency services worker, had reported blue marks on the body. Navalny's relatives have not yet been granted access to his body. Polar Wolf lies some 50 kilometres due north of Salekhard.
According to the Russian authorities, Navalny collapsed while exercising in freezing conditions. Attempts to revive him failed.
Human rights activists have termed his death a murder, and Navalny's death has drawn condemnation from leaders of several countries, including US President Joe Biden.
Navalny's mother, Lyudmila Navalnaya, has been attempting without success to collect the body.
According to Novaya Gazeta's informant, the blue marks show where he was held by penal colony staff after suffering cramp. A bruise on his chest was evidence of attempts at resuscitation, the informant said.
The report makes clear that the informant did not see Navalny's body after death, but gained the information from a colleague.
The OVD-Info Russian human rights media organization reported on Sunday that more than 12,000 people had supported an appeal to the investigating commission for Navalny's body to be released.
OVD-Info launched the appeal on Saturday afternoon, calling for the body to be released to the deceased dissident's relatives "as quickly as possible."
Events commemorating Navalny and his opposition to Russian President Vladimir Putin's rule have been held all round the world, frequently in front of Russian embassies. More than 400 people have been detained in Russia while marking his death.
