When the owner of the independent network NTV, Vladimir Gusinsky, was arrested in 2000, it was Mr. Lesin who visited him in prison and pressed him to sign a legally dubious agreement that dropped the criminal charges. He did so in exchange for the sale of the station to Gazprom “at a price to be determined by Gazprom,” according to a 2004 ruling by the European Court of Human Rights.

In Mr. Putin’s second term, Mr. Lesin served as a senior presidential adviser in the Kremlin, and, most significant, started Russia Today, the nation’s first 24-hour all-news television network broadcasting in English (and later other languages). Known today simply as RT, the network has become a potent weapon in the information war the Kremlin believes it is fighting against the West.

Mr. Lesin’s position in the Kremlin ended in 2009 when he had a falling out with Mr. Putin’s successor for one term, Dmitri A. Medvedev. He was dismissed, one of Mr. Medvedev’s aides told Interfax, because of his “failure to observe the rules and ethical behavior of state service.” That was apparently a reference to his continued business interests in an industry he formally oversaw.

He returned, though, after Mr. Putin assumed the presidency for a third term. In October 2013, he took over Gazprom Media, the subsidiary of the energy giant that through a complicated ownership structure is controlled by one of Mr. Putin’s confidants, Yuri V. Kovalchuk, the main shareholder of Bank Rossiya. Mr. Kovalchuk and Bank Rossiya each face sanctions by the United States for their ties to Mr. Putin.

Within two months, Mr. Lesin oversaw the acquisition of Prof-Media, a subsidiary of one of Russia’s richest industrialist, Vladimir O. Potanin. Prof-Media owned television networks like MTV Russia, as well as radio stations and magazines. The deal, reported to be worth $600 million at the time, was seen as the Kremlin’s effort to bring even more independent media outlets under state political and financial control.

“There is a danger that Lesin will use his administrative resources not only to serve the interests of his bosses, but also to settle old scores,” a columnist, Yulia Latynina, wrote in The Moscow Times in December 2013.

Mr. Lesin did clash with the remaining vestiges of independent news media. Aleksei A. Venediktov, the editor of the radio station Ekho Moskvy, which is partly owned by Gazprom Media but ostensibly independent, said Mr. Lesin had invited him to dinner at one of Moscow’s fanciest restaurants and pressed him to dismiss several journalists who appeared on the air or on the station’s website, including Ms. Latynina.