Lawyers for Russian opposition leader Alexei Navalny say they have not yet been granted access to their client.
According to an ally, it has been transferred to Khimki, near the capital Moscow. According to opposition member Leonid Volkov, Navalny would be allowed to receive a member of his legal team in the course of the morning.
Russian authorities arrested the 44-year-old politician on Sunday after arriving at an airport in Moscow after spending months in Germany.
Navalny is suspected of violating the terms of a suspended prison sentence imposed on him. Several Western countries have demanded the release of President Vladimir Putin’s prominent opponent.
The Russian prison service says Navalny will at least remain in prison until he is due to appear in court later this month.