Pavel Zelensky, a member of the Anti-Corruption Foundation team of Kremlin critic Alexei Navalny, was jailed by a Moscow court on Saturday until February 28 on charges of inciting extremism on the internet, according to a court statement.His detention by the Presnensky District Court comes a day before Navalny's planned return to Russia since being poisoned in August and evacuated to Germany where he has been recuperating. Zelensky is a camera operator for the opposition leader's Anti-Corruption Foundation, which specializes in publishing high-impact investigations into what it says is official graft. Some of those targeted have disputed its findings and taken successful legal action.He was detained on Friday, the head of Agora, a Moscow-based human rights group, said on social media, and will now spend over a month in pre-trial detention.Zelensky's case revolves around a tweet posted last October, Agora cited the camera operator's lawyer as saying.The tweet contained a photo of Irina Slavina, a Russian journalist who died after setting herself on fire in front of a branch of the Interior Ministry a day after her apartment was searched by police.The social media post expressed anger at the government and called for people to take any feelings of protest offline."(We) will not give up and will help Pasha Zelensky's family in every way possible," Ivan Zhdanov, director of the Anti-Corruption Foundation, said on Twitter after the court hearing.Navalny last week announced his plan to return to Russia on January 17, signaling his intention to continue his political struggle against Russian President Vladimir Putin, whom he accuses of ordering his poisoning with the Novichok nerve agent.His return poses a conundrum for the Kremlin: jail him and risk protests, punitive Western action and creating a political martyr; or do nothing and risk looking weak.Putin has denied the authorities tried to poison Navalny and said Russian agents would have finished the job if they had wanted him dead. The Kremlin has said it has seen no evidence Navalny was poisoned and that he is free to return to Russia at any time.