Top Russian opposition leader Alexei Navalny was found guilty on Tuesday of slandering a lawmaker and ordered to pay a hefty fine, the latest legal case against the prominent critic of President Vladimir Putin.
Navalny shot to prominence during huge anti-Putin rallies in 2011-2012 and last year won strong support in Moscow mayoral elections, polling more than 27 percent of the vote.
Navalny was found guilty of calling municipal lawmaker Alexei Lisovenko "a lawmaker-drug addict" and ordered to pay 300,000 rubles ($8,300, 6,000 euros), an AFP correspondent reported from the Babushkinsky district court in Moscow.
His supporters say the guilty verdict could further deepen Navalny's legal woes and see him jailed.
He is already being held under house arrest while awaiting trial in a separate embezzlement case opening Thursday. And last year he was given a suspended five-year sentence in another case over timber embezzlement.
Navalny's team wrote on his popular blog after Tuesday's court decision that the latest guilty verdict could lead to a ruling turning his suspended sentence into a real one.
In February, Navalny was banned from using the Internet in a move he said was aimed at thwarting his fight against top-level corruption.
Navalny's spokeswoman Anna Veduta said the authorities could transfer him from his apartment to a pre-trial detention centre as early as Thursday, warning they could use the slander verdict as a pretext.
Along with his brother Oleg, Navalny faces charges of stealing and laundering millions of rubles from French cosmetics company Yves Rocher and a Russian firm.
Last month, the Russian authorities blocked Navalny's popular blog, which he had used to expose corruption among the elites. State television also aired a documentary accusing him of having contacts with the US Central Intelligence Agency.