The United Nations has accused Russia of extensive human rights violations in Crimea, which was annexed in 2014, in a report published on Thursday.
The Russian domestic intelligence service (FSB) tortured at least six people, it said.
A freelance journalist was forced to make a "confession" about alleged cooperation with Ukrainian secret services that was later shown on Russian state television, the report said.
As an occupying power, Moscow should not promote the transfer of Russians into the occupied territory, the authors of the report said.
More than 200,000 Russian citizens have moved to Crimea since 2014, according to Russian official statistics.
At the same time, nearly 50,000 former residents of Crimea are registered as refugees in Ukraine.
Kiev has repeatedly accused Moscow of a targeted transfer of population in order to consolidate Russia's power in the area.
Furthermore, no investigations have yet been launched into the disappearance of 43 people, of whom 11 are still missing, since Russia first annexed the area, the report said.
At least one person was abducted and was proven to have been killed.
Opponents of the annexation were tried in absentia by the local rulers without the possibility of sufficient defence. Sentences were handed down based on anonymous witness statements, while those tried had limited access to legal representation.
Russians also targeted minorities with arbitrary arrests and raids against religious communities including the Crimean Tatar Muslim minority and Jehovah's Witnesses, banned in the report said.
Few states worldwide have recognised Russia's annexation of Crimea, which is still considered part of Ukraine.
