Russian investigators said they had conclusive proof that the opposition wanted to organise unrest in the country and even underwent training abroad to learn how to stage a coup.
In an unusual television special broadcast Friday evening, the spokesman of the powerful Investigative Committee said that leftist activists currently arrested in Moscow "prepared very carefully for the mass riots."
"This preparation was happening outside of Russia," spokesman Vladimir Markin told the Rossiya channel. "They were trained abroad in methods of mass unrest to be used with the goal of regime change, using the example of 'orange revolutions'."
Russia charged three people last month with preparing for mass riots in Russia, including 39-year-old Leonid Razvozzhayev, who told rights activists that he was forced to pen a confession after being kidnapped from Ukraine and terrorised for several days.
Despite Razvozzhayev's retraction of the confession, Russia has "irrefutable evidence" of his and two other activists' involvement in plotting unrest, the Investigative Committee said in a statement.
The television programme that ran Markin's interview also showed a young woman who claimed she was Razvozzhayev's lover and knew that he and other accused activists -- Left Front movement leader Sergei Udaltsov and Udaltsov's assistant Konstantin Lebedev -- met Georgian MP Givi Targamadze, as the investigation claims.
"The money started appearing in spring and the beginning of summer," the woman, Samira Bader, said on the programme, which alleged that Razvozzhayev suddenly became rich with his foreign sponsor's cash.
The high-profile investigation was launched after a pro-Kremlin channel aired a film alleging the accused trio plotted a violent coup together with Targamadze's money and expertise in Georgia's pro-western Rose Revolution of 2003.
Targamadze and Udaltsov, who has not yet been arrested, have vehemently denied the film's claims.