Leading Russian dissident Alexei Navalny, who blames the Kremlin for poisoning him, is planning to return to Moscow on Sunday.
"On January 17, Sunday, I will return home on a Pobeda flight," Navalny wrote on Twitter on Wednesday. "Meet (me)."
The airline Pobeda has a connection from Berlin's capital airport BER to Moscow in its flight schedule for Sunday, landing at 7.20pm local time at the Russian capital's Vnukovo Airport.
After an attempted assassination with the nerve agent Novichok, Navalny has been recovering in Germany since August.
He wrote on Twitter that he never considered staying outside Russia as he had never left his homeland of his own free will.
"I arrived in Germany in a resuscitation box," he said.
The activist, one of Russian President Vladimir Putin's most prominent critics who was previously jailed for his opposition activities, fell ill on a domestic flight on August 20 before being transported to Germany for treatment two days later.
The Charite hospital in Berlin announced on September 23 that he had been discharged after his condition "improved sufficiently".
Laboratories in Germany, France and Sweden have determined that Navalny was poisoned with the nerve agent Novichok.
The European Union has imposed sanctions on Russia over the poisoning.
Navalny has blamed the poisoning on the FSB, the Russian secret service, under Putin's orders.
Putin has dismissed the allegations.
Russian officials initially refused to accept that he had been poisoned at all.
The Russian authorities have increased the pressure on Navalny, revealing on Tuesday that he could face further jail time for violating the rules of his probation, arising from a conviction in 2014.
A legal application had been submitted to a Moscow court.
Navalny maintains that the probation conditions became invalid on December 30.
Shortly before the turn of the year, Russian authorities asked Navalny in writing to meet the requirements of the earlier sentence and to report to them in person or risk imprisonment.
The dissident is also being investigated for alleged fraud, with a Russian investigative committee accusing him of misappropriating the equivalent of about $US4.2 million ($A5.4 million) in donations to his anti-corruption fund to buy property and finance private holidays.
Navalny has denied the allegations and accused the Kremlin of trying to intimidate him into not returning to Russia.
"You're doing everything to scare me," Navalny said in a video posted to Instagram on Wednesday, adding that he had always pledged to return to his work in Russia.
Political scientist Tatiana Stanovaya said that the Kremlin had left itself little choice but to arrest Navalny on his return.
Failure to do so would likely be interpreted as weakness by the secret services and other security structures.
"They were betting that he wouldn't come back," she said.