The ruling concluded an hours-long court hearing set up at a police precinct where the politician was held since his arrest at a Moscow airport Sunday. 

Navalny flew to Russia from Germany, where he had spent five months recovering from nerve agent poisoning that he blames on the Kremlin. He was detained at passport control at Sheremetyevo airport after flying in Sunday evening from Berlin, where he was treated following the poisoning in August. 

Navalny's arrest prompted a wave of criticism from US and European officials, adding to existing tension between Russia and West. 

German Foreign Minister Heiko Maas noted that Navalny had returned of his own volition and said "it is completely incomprehensible that he was detained by Russian authorities immediately after his arrival.” 

“Russia is bound by its own constitution and by international commitments to the principle of the rule of law and the protection of civil rights,” Maas added. 

“These principles must of course also be applied to Alexei Navalny. He should be released immediately.” 

The politician's allies said Monday he was being held at a police precinct outside Moscow and has been refused access to his lawyer. 

The court hearing into whether Navalny should remain in custody was hastily set up at the precinct itself, and the politician's lawyers said they were notified minutes before. 

“It is impossible what is happening over here,” Navalny said in video from the improvised court room, posted on his page in the messaging app Telegram. 

“It is lawlessness of the highest degree.” 

Calls for Navalny's immediate release have come from European Commission President Ursula von der Leyen, the office of the UN High Commissioner for Human Rights, British Foreign Secretary Dominic Raab and top officials of other EU nations. 

US President-elect Joe Biden's pick for national security adviser called on Russian authorities to free Navalny. 

“Mr Navalny should be immediately released, and the perpetrators of the outrageous attack on his life must be held accountable,” Jake Sullivan tweeted. 

The outgoing US secretary of state, Mike Pompeo, said the US “strongly condemns” the decision to arrest Navalny. 

Nevertheless, the judge ordered that Navalny be remanded in custody until Feb 15, Yarmysh said on Twitter. Navalny''s lawyer Vadim Kobzev told the Interfax news agency that the defense plans to appeal the ruling. 

Navalny's detention was widely expected because Russia's prisons service said he had violated probation terms from a suspended sentence on a 2014 money-laundering conviction. 

The service said it would seek to have Navalny serve his 3½-year sentence behind bars.