- Police seized Russian opposition leader Alexei Navalny at a border control post at Moscow's Sheremetyevo airport less than an hour after he returned to Russia from Germany.
- He has repeatedly led large-scale street protests against Russia President Vladimir Putin, most recently in the summer of 2019.
- In a video posted from inside the hearing, Navalny said he did not understand how a court session could take place at a police station - he was brought into a courtroom set up at a police station in Khimki.
Russian opposition leader Alexei Navalny said on Monday his treatment was beyond a "mockery of justice" as he was brought before a hastily organised court a day after his dramatic airport arrest.
With calls growing in the West for Navalny's release, he was brought into a courtroom set up at a police station in Khimki on the outskirts of Moscow where he was taken following his detention on Sunday night.
Police seized Navalny, President Vladimir Putin's most prominent opponent, at a border control post at Moscow's Sheremetyevo airport less than an hour after he returned to Russia from Germany for the first time since he was poisoned with a nerve agent in August.
In a video posted by his team from inside the hearing, an incredulous Navalny said he did not understand how a court session could take place at a police station and why no one had been notified until the last minute.
"I've seen a lot of mockery of justice, but the old man in the bunker (Putin) is so afraid that they have blatantly torn up and thrown away" Russia's criminal code, Navalny said.
"This is ultimate lawlessness."
In another video, Navalny called for the hearing to be open to all journalists, after only pro-Kremlin media were allowed to attend.
"I demand that this procedure be as open as possible, so that all media have the opportunity to observe the amazing absurdity of what is happening here," he said.
About 100 people, mostly journalists, had gathered in the snow outside the police station and several police vans were waiting nearby with their engines running.
Russia's FSIN prison service said Sunday that it had detained Navalny, 44, for violating the terms of a suspended sentence he was given in 2014, on fraud charges he says were politically motivated.
Navalny is also facing potential new criminal charges under a probe launched late last year by Russian investigators who say he misappropriated over $4 million worth of donations.
The leading Kremlin critic emerged a decade with his Anti-Corruption Foundation publishing anti-graft investigations that often reveal the lavish lifestyles of the Russian elite.
He has repeatedly led large-scale street protests against Putin, most recently in the summer of 2019, and was gearing up for another challenge to authorities during elections to the lower house State Duma in September.
He was evacuated to Germany after falling violently ill on a flight over Siberia in August from what Western experts eventually concluded was a poisoning with Soviet-designed nerve agent Novichok.
Navalny accused Putin of ordering the attack, a claim the Kremlin vehemently denies. Russian police have not opened an investigation citing a lack of evidence.
His arrest on Sunday drew widespread Western condemnation, with the United States, European Union, France and Canada all calling for his release.
Others joined that call on Monday, with EU chief Ursula von der Leyen saying Russian authorities should "immediately release him and ensure his safety".
The United Nations human rights office said it was "deeply troubled" by the arrest, while German Foreign Minister Heiko Maas said it was "totally incomprehensible".
Britain's Foreign Secretary Dominic Raab condemned the detention as "appalling".
"He must be immediately released. Rather than persecuting Mr Navalny Russia should explain how a chemical weapon came to be used on Russian soil," Raab wrote.
Navalny was poisoned with the same chemical said to have been used in the attempted murder of former spy Sergei Skripal in the English town of Salisbury in 2018.
Russia has hit back at the condemnation, with Foreign Minister Sergei Lavrov on Monday saying it was an attempt to distract attention from domestic problems in Western countries.
"It looks like Western politicians see this as an opportunity to divert attention from the deepest crisis the liberal development model has found itself in," he said.
Russia frequently accuses the West of unfair criticism of its domestic policies pointing to divisions in Western countries like those that led to the storming of the US Capitol or the Yellow Vests protests in France.