Mikhail Svetov, the head of Russia's opposition Libertarian Party, has denied allegations by Moscow prosecutors that he engaged in "immoral activities" with a minor, after he was questioned by investigators for about 12 hours beginning on November 6.

Svetov and his supporters claim the allegations are a politically motivated response to his increasingly vocal opposition to the government of President Vladimir Putin.

"I think that [all my political activity] had a cumulative effect, and my lecture tour was the last straw," Svetov, who spoke to audiences in 29 provincial cities over about six weeks recently, told the Russia-focused news site Meduza.

"They have always tried to marginalize us libertarians, trying to show that we are a purely Moscow phenomenon, as if our ideas were just some hipsterism from the capital. And suddenly I clearly demonstrated that all of Russia is interested in my ideas," he said. "The authorities understood that they had missed something important and that is why now they are trying to frighten me."

In August, Svetov was sentenced to 30 days in jail by a court that ruled he violated laws on conducting public demonstrations in connection with his role in a wave of demonstrations that swept Moscow over the authorities' refusal to register independent candidates to run for the Moscow city council.

In response to Svetov's questioning, activists in Moscow and other cities began holding one-person protests in his support late on November 6. The demonstrations continued on November 7 and 8.

The accusations stem from Instagram posts Svetov made in 2012 featuring his then-girlfriend, Anastasia Starodubovskaya. Starodubovskaya was also questioned for about 12 hours, according to Libertarian Party activist Vera Kichanova.

Svetov, 34, said in an interview with Czar.TV that investigators were alleging that Starodubovskaya was under the age of 16 when she was involved with Svetov.

He also said Starodubovskaya was being pressured by investigators to testify against him.

So far, no criminal charges have been filed, and both Svetov and Staroduboskaya are being questioned as witnesses.

Svetov and his lawyer, Mikhail Biryukov, said on November 7 that the allegations against him stemmed from a denunciation sent to the authorities in August by an unnamed journalist working for the pro-Kremlin daily Izvestia.

Izvestia has issued a statement saying that "no one from the editorial office of...Izvestia wrote any declarations to law enforcement organs."

Biryukov also told journalists that Svetov was being required to undergo a "urological examination" and that his home had been searched.

On August 13, the communications watchdog agency Roskomnadzor added Svetov's Instagram account to the government's list of banned Internet sites. At the time, state news agency RIA Novosti reported that the step was taken because the page -- which had not been updated since 2016 -- contained "illegal content (child pornography)."

'Keep Quiet, Or Else'

Svetov has now become one of many people at odds with local or federal authorities in Russia who have found themselves the target of child pornography or pedophilia allegations.

Historian Yury Dmitriyev, who conducted ground-breaking research into Soviet crimes in the Karelia region under dictator Josef Stalin, was initially charged with taking "pornographic" photographs of his foster daughter. He maintains he took the photographs at the request of social workers to monitor the development of the frail child. After he was acquitted of those charges, authorities soon rearrested him on more severe charges of child sexual assault. That case is still pending.

In May, another Karelia historian, Sergei Koltyrin, was convicted of having sex with a minor and was sentenced to nine years in prison. Prior to his arrest in October 2018, Koltyrin told several people that he feared repercussions because of his opposition to government-backed efforts to "prove" that Stalin-era executions in the Karelia region had actually been carried out by Finns against Soviet prisoners of war.

"They told me to shut my mouth and keep quiet, quieter than a mouse," he told a journalist.

In April 2015, Soviet-era dissident Vladimir Bukovsky was charged in England over pornographic images of children found on his computer. He claimed at the time that he was the victim of a revenge plot by the Russian secret services, but a British expert later testified that there was no evidence the images were planted. The trial was suspended due to ill health and the case was still pending when Bukovsky, who pleaded not guilty, died on October 27.

In December 2017, French citizen Yoann Barbereau completed a harrowing escape from Russia, fleeing child-pornography and pedophilia charges in the Siberian city of Irkutsk, where he had been the local director of the nonprofit Alliance Francaise cultural organization. He was arrested in February 2015 and spent 16 months under house arrest during his trial.

In September 2016, while awaiting a verdict, he fled to Moscow and made his way to the French Embassy. He spent 14 months hiding in the embassy before setting off on foot to a Baltic country that he declined to name.

In June 2015, Lithuanian police visited the home of Konstantin Rubakhin, a Russian environmental activist who was seeking political asylum in the country after being harassed and beaten in Russia. Police told him they were investigating allegations of child pornography, allegations that Rubakhin believed were planted by the Russian security services to thwart his asylum application. The authorities in Lithuania quickly dropped the case.

In 2013, Russian opposition activist and blogger Rustem Adagamov fled Russia amid pedophilia allegations that he denied as "insane." The accusations were made by Adagamov's former wife in an interview with Russia's state-controlled RT television network.

Raising suspicions that someone is a pedophile suits "the Kremlin's line that human rights activists are all just degenerates," Vytas Jurkonis, a Lithuanian human rights activist, told The New York Times in December 2016.

In April 2015, shortly after learning about the charges against dissident Bukovsky, Margarita Simonyan, the editor in chief of RT, wrote on Twitter: "The pedophile's plan: rape a child, sign up for the opposition, emigrate, expose from abroad all the sins of the Motherland, and all will be well. Or not."