MOSCOW -- Blurry video of highly placed men engaging in sexual acts, audio recordings of influential figures profanely insulting their nominal allies -- in Russia these appear enough that a special word has evolved: "kompromat," or "compromising material."

In the wake of unsubstantiated allegations that Russia has gathered kompromat against President-elect Donald Trump, Kremlin spokesman Dmitry Peskov brushed them off as an attempt to undermine potentially improved U.S.-Russia ties once Trump takes office.

"The Kremlin does not engage in collecting compromising information," he told reporters on Wednesday.

But such material has shown up in Russia for decades. Recent examples of kompromat often support Kremlin interests or appear via media believed to have close ties to President Vladimir Putin's administration.

Some notable examples:

VICTORIA NULAND

As demonstrations against Ukraine's Russia-friendly President Viktor Yanukovych spiraled in February 2014, an audio recording emerged apparently of Nuland, an assistant U.S. secretary of state, and U.S. Ambassador Geoffrey Pyatt discussing which opposition leaders Washington would like to see as prime minister.

The recording's initial release was presented as evidence of open American instigation in the turmoil. But what attracted much of the attention was Nuland's obscene dismissal of the European Union, whose envoys the U.S. regarded as indecisive and slow-moving in the crisis.

The recording was widely believed to have been made by Russia. Nuland herself called it "impressive tradecraft."

MIKHAIL KASYANOV

Kasyanov was Putin's first prime minister before becoming one of the more prominent figures in Russia's beleaguered and fragmented opposition. His party was running in last year's parliamentary election and he also has been seen as a possible dark horse challenger to Putin in the 2018 presidential election.

In March 2016, grainy video was broadcast that appeared to show Kasyanov and a woman identified as an opposition activist having sex and speaking dismissively of other opposition figures. The video appeared on NTV, a state-controlled TV channel noted for especially vehement criticism of the opposition and support for Putin.

BORIS NEMTSOV

Before he was assassinated on a bridge near the Kremlin in 2015, Nemtsov was one of the most determined and charismatic of Putin's opponents. He was a leading figure in the massive anti-Kremlin demonstrations in Moscow in late 2011 following parliamentary elections plagued by allegations of fraud.

The size and persistence of the demonstrations apparently caught officials by surprise and sent them scrambling for ways to tamp them down without mass arrests.

On the eve of one of the planned protests, the website Life News, closely connected with the Kremlin and Russian security services, released recordings of Nemtsov apparently insulting other notable opposition figures. The recordings reinforced the personal and tactical disagreements that have undermined the opposition.

Nemtsov said some of the recordings were manipulated or faked but acknowledged that some were authentic.

YURI SKURATOV

In 1999, Boris Yeltsin was president while Putin headed the FSB security agency, apparently positioning himself to take over from Yeltsin.

Skuratov, at that time Russia's prosecutor-general, had been investigating corruption in the Yeltsin administration; Yeltsin tried to fire him, but the parliament refused.

A videotape appeared on state television of a man resembling Skuratov apparently having sex with prostitutes, prompting parliament to suspend him. Putin publicly identified the man as Skuratov.

Weeks after Putin became acting president on New Year's Eve 1999, the parliament dismissed Skuratov.