Navalny was abducted by police officers at the border without explanation, his spokesperson Kira Yarmysh tweeted.
His lawyer, who was also flying from Berlin, was not allowed to accompany the opposition leader, he said.
The couple were returning from a five-month stay in Germany, where they were recovering from Novichok’s poisoning.
They landed in Sheremetyevo shortly after 8 p.m. local time, according to flight data information.
“This is the best day in the last five months,” Navalny told reporters at the airport just before his arrest.
“Everyone asks me if I’m afraid. I’m not afraid,” he said.
“I feel completely fine walking towards border control.
“I know I will leave and go home because I am right and all criminal cases against me are fabricated.”
Like a perennial thorn in the side of Russian President Vladimir Putin, Navalny was placed on the country’s federal wanted list during his convalescence abroad for violating probation terms related to a years-long fraud case.
Mr. Navalany dismisses the case for political reasons.
“Officers … detained Alexey Navalny, who was sentenced to suspended sentences, and who has been on the wanted list since December 29, 2020 for repeated violations of the probationary period. Until the court ruling, he will be in custody.” , said. a statement from the Federal Penitentiary Service, according to TASS.
After Navalny’s poisoning with military-grade Novichok in August, a joint investigation by CNN and the Bellingcat group implicated the Russian Security Service (FSB) in the poisoning, reconstructing how an elite unit of the agency followed Navalny’s team during a trip to Siberia in August, where Navalny was poisoned and fell ill on a flight to Moscow.
The investigation also found that this unit, which included chemical weapons experts, had followed Navalny on more than 30 trips to and from Moscow since 2017.
Russia denies its involvement in the Navalny poisoning. But several Western officials and Navalny himself have openly blamed Russia.
Diverted flight to Sheremetyevo
Originally, Mr. Navalny was scheduled to land at Vnukovo airport, where a crowd of hundreds of supporters and journalists waited. CNN has not been able to establish why the flight was diverted.
Russian media broadcasts showed police arresting several allies waiting for them in Vnukovo, despite temperatures of around -20 degrees Celsius (-4 degrees F), including politician and lawyer Lyubov Sobol and Ruslan Shaveddinov, who works for the Navalny Anti-Corruption Foundation.
The 2.5-hour Navalny flight of Russian airline Pobeda took off from Berlin Brandenburg Airport on Sunday afternoon.
Before leaving, he had thanked all the other passengers on his flight, according to a live broadcast on TV Rain. “Thank you all, I hope we arrive well,” he said. “And I’m sure everything will be absolutely great.”
In an Instagram post on Saturday, Navalny thanked Germany, adding that Germans were “nice, understanding and friendly people.”
“Doctors and nurses. Physiotherapists and policemen. Many policemen. Neighbors who invited us to drink and those who allowed us to rent. Politicians and lawyers. Merchants. Journalists.
“The prosecutors who questioned me at the request of Russia. Coaches. Teachers. And even, once, the Chancellor. I had a fairly wide circle of friends here. And I can only thank everyone.”
Navalny is an outspoken critic of the government and has been detained by the Russian authorities many times.
In 2014, he was convicted of fraud after he and his brother Oleg were charged with embezzlement of 30 million rubles ($ 540,000) from a Russian subsidiary of French cosmetics company Yves Rocher.
While Mr. Navalny received a suspended sentence, his brother was imprisoned. Mr. Navalny maintains that the case is politically motivated.
FSIN has accused Mr. Navalny of violating the terms of his suspended sentence by failing to show up for scheduled inspections, and requested that the court replace his suspended sentence with an actual prison sentence.
A hearing has been scheduled for January 29. If the FSIN’s request is granted, Navalny is likely to be incarcerated for 3.5 years.
If Navalny is not convicted by the end of January, he will still face an investigation into a more recent fraud case, in which he and his Anti-Corruption Foundation have been accused of misusing donations from supporters.
“The situation with Navalny looks like two trains running towards each other at full speed, destined to collide,” said Tatyana Stanovaya, a fellow visitor, also at the Carnegie Center in Moscow.
“There will be many victims.”
In fact, the attacks on Navalny’s allies have continued.
Pavel Zelensky, a cameraman for the Navalny Anti-Corruption Foundation, was arrested on Friday and will be detained until the end of February.
According to Agora, a Russian human rights organization, Zelensky was accused of extremism for the September tweets, in which he blamed the government for the self-immolation of journalist Irina Slavina.
Before taking her own life, Slavina blamed pressure from Russian police for her decision to self-immolate.