MOSCOW, Russia — Three leading Russian liberals have come under attack in a smear campaign reminiscent of Soviet-era tactics against those who went against the grain of official thought.

Ilya Yashin, a leader of the opposition Solidarity movement, Mikhail Fishman, editor of the Russian edition of Newsweek, and Dmitry Oreshkin, an independent political analyst, found themselves playing starring roles as bribe-givers in a YouTube video that went viral last week.

The video presents an anonymous caller ringing the three men and asking if they have ever given bribes to Russia’s notoriously corrupt traffic police. Fishman and Oreshkin openly say that they have. The four minute-long video intersperses the three men’s answers with images of their bribe-giving inside a cop car, from different angles, with the policemen’s faces blurred out. All three appear surprised when the cops refuse to take the bribe, responding instead with a hearty lesson: “Don’t break the rules — and don’t offer money!”

That video had little effect. Russia’s traffic police are among the country’s least loved — just 23 percent of Russians trust them according to a 2008 poll by the Public Opinion Foundation. That feeling has only solidified in the past few months amid a spate of outrageous scandals (earlier this month, Russian traffic police came under fire for forcing random drivers to set up a “human shield” with their cars on one of Moscow’s main thoroughfares in order to stop a runaway criminal).

Yashin and Fishman said the video was doctored, with words put in their mouths. The supposed police were actors, they said. Many people simply rolled their eyes. “Yeah everyone gives traffic police money — there’s nothing really horrible here,” wrote one Russian YouTube commenter.

Then on Tuesday, a new video appeared.

In addition to the alleged bribing, the second half of the video, titled “Fishman-Drug Addict” shows a man who appears to be Fishman sitting near a half-naked girl, her face blurred out. He sits before a stool, carefully cutting a white powder with a credit card and then snorting it. The video fades with Russian music accompanying a nude Fishman getting dressed.

By then, it was clear a campaign was underway.

In a telephone interview on Wednesday, Yashin accused people close to Russia’s highest powers of ordering the campaign.

“The scale of these special operations — and these aren’t even provocations, but special operations — is huge. It costs a lot of money to organize, to get people involved,” he said. “Whoever did it — the police or the security services — they need an order. That’s how they function.”

“That’s why I’m sure those who ordered this are close to the presidential administration,” Yashin said.

The video first got attention after appearing on the website of Nashi, the pro-Putin youth group created by Vladislav Surkov, deputy of the presidential chief of staff and the Kremlin’s chief ideologist.

Yashin declined to implicate Surkov directly.

A source inside the presidential administration said any suggestion of the Kremlin’s involvement was “pure idiotism.”

“Anything that happens that people don’t like, it’s easiest to blame the Kremlin. Who’s guilty? Of course, the Kremlin. And, let me guess, the security services,” the source said.

“We will not sink to their level and give an official comment,” the source said.

Yashin took to his blog on Wednesday to warn that further material could be forthcoming. After viewing the second video, he said he recognized its location, an apartment that he said belonged to a model named Katya Gerasimova. Yashin said he ended his brief affair with Gerasimova last year after suspecting her of collecting blackmail on him, following a bizarre meeting in which they engaged in a threesome, she tried to lure him with sex toys and implored him to roll a joint.

“At that moment, everything became as clear as day,” he writes.

Fishman would not comment on the case. Russian Newsweek, along with The New Times, is Russia’s leading liberal magazine, and features hard-hitting reporting on Russian political intrigue, as well as police and military affairs.

In the interview, Yashin said he believed the timing of the campaign was linked to the Kremlin’s increasing worry over its falling popularity.

“Times aren’t easy for the Russian leadership — their disapproval rating is growing,” he said. “They’re leading people away from worrying about important things like politics, and putting attention on things like traffic police, scandals, yellow gossip."

One person close to affair, who asked not to be identified, saw a larger campaign underway.

“They’ve chosen one politician, one journalist, one analyst,” the person said. “It looks like an attack on liberal society in general.”

On Tuesday, the chief editors of Russia’s leading press — including the Kommersant and Izvetsia dailies, the Moskovsky Komsomolets tabloid, and Russia’s best-selling newspaper Argumenty i Fakti — signed a letter in public support of Fishman.