MOSCOW—The public airing of a dossier Tuesday on President-elect Donald Trump casts a spotlight on Russia’s dark art of kompromat, the practice of collecting compromising material on prominent individuals for the purposes of blackmail.

The dossier is packed with unverified allegations, including a claim that Russian officials obtained evidence of Mr. Trump with prostitutes and kept the information in reserve as potential blackmail.

Mr. Trump has dismissed the reports. “Intelligence agencies should never have allowed this fake news to ‘leak’ into the public,” Mr. Trump said on Twitter on Wednesday. “One last shot at me.”

The Kremlin has denied any link to the dossier, and Kremlin spokesman Dmitry Peskov called the reports “pulp fiction,” according to Russian news agencies.

Kompromat, a contraction of the Russian phrase “compromising materials,” has a rich history in Russia dating back to the Soviet era. Diplomats, politicians and bureaucrats have all been embarrassed by leaked videos or other material.

While blackmail is by no means unique to Russia, the deployment of kompromat is a regular feature in the country’s bare-fisted domestic politics.

Early last year, the pro-Kremlin television network NTV aired hidden-camera footage of Mikhail Kasyanov, leader of the opposition party Parnas.