(CNN)Yevgeny Prigozhin is a Russian oligarch dubbed "chef" to President Vladimir Putin by the Russian press. In 2002, he served caviar and truffles to President George W. Bush during a summit in St. Petersburg. Before that, he renovated a boat that became the city's most exclusive restaurant.
Exclusive: Putin's 'chef,' the man behind the troll factory
But his business empire has expanded far beyond the kitchen. US investigators believe it was Prigozhin's company that financed a Russian "troll factory" that used social media to spread fake news during the 2016 US presidential campaign, according to multiple officials briefed on the investigation. One part of the factory had a particularly intriguing name and mission: a "Department of Provocations" dedicated to sowing fake news and social divisions in the West, according to internal company documents obtained by CNN.
Prigozhin is one of the Kremlin's inner circle. His company is believed to be a main backer of the St. Petersburg-based "Internet Research Agency" (IRA), a secretive technology firm, according to US officials and the documents reviewed by CNN. Prigozhin was sanctioned by the US Treasury Department in December of 2016 for providing financial support for Russia's military occupation of Ukraine. Two of his companies, including his catering business, were also sanctioned by Treasury this year.
CNN has examined scores of documents leaked from Prigozhin's companies that show further evidence of his links to the troll factory.
One contract provided IRA with ways to monitor social media and a "system of automized promotion in search engines."
Other documents show that the monthly budget for IRA was around $1 million in 2013 -- split between departments that included Russian-language operations and the use of social media in English. The "Department of Provocations" offers this mission: "how do we create news items to achieve our goals."
Another document shows a 2013 contract drawn up by an employee at Concord Management and Consulting, Prigozhin's main business, based in St. Petersburg. The contract was for 20 million rubles (then $650,000) for construction work at the IRA and was signed by the director general of IRA.
Additionally, company records reviewed by CNN show that an employee at Concord Consulting subsequently joined IRA.
Several emails and calls from CNN to Concord Consulting went unanswered. The IRA no longer exists.
Prigozhin is notoriously image-conscious. Last year, he filed 15 lawsuits against the Internet company Yandex, using a Russian law that obliges online search engines to remove "illegal, inaccurate, or irrelevant information." The case was subsequently dropped.
The Internet Research Agency has long been in the crosshairs of US investigations. A declassified assessment by the US intelligence community published in January concluded that the "likely financier of the so-called Internet Research Agency of professional trolls located in Saint Petersburg is a close Putin ally with ties to Russian intelligence," though it did not name Prigozhin.
Prigozhin has a colorful past. He spent nine years in prison in the 1980s for fraud and robbery, according to Russian media reports. After his release, he went into the catering business -- renovating a boat and opening New Island, one of a half-dozen upscale restaurants he owns in St. Petersburg. Putin turned to him to cater his birthday parties as well as dinners with visiting leaders, including President Bush and Jacques Chirac of France. A headline in The Moscow Times referred to Prigozhin as Putin's "Personal Chef."
Prigozhin subsequently won lucrative catering contracts for schools and Russia's armed forces. He escorted Putin around his new food-processing factory in 2010. By then he was very much a Kremlin insider with a growing commercial empire.
The Internet Research Agency was based at 55 Savushkina Street in St. Petersburg before it officially ceased operations on December 28, 2016. But investigative journalist Andrei Zakharov, who works for the business media group RBC, says its work continues.
"They have a lot of legal entities," Zakharov says, "and they still, I think, change it every year or every two years."
Company registrations retrieved by CNN appear to confirm that. Another company at 55 Savushkina Street is Glavset, whose director general has the same name as the boss of IRA. The name matches that of a former regional police chief in St. Petersburg.
CNN has also tried to reach Glavset's management without success.
Glavset lists the "creation and use of databases and information resources" as well as the "development of computer software, advertising services and information placement services" among its activities. It was listed as a company in the Russian legal entities registry in February 2015.
A short time later, it began advertising for staff on a headhunting site (hh.ru). One post looking for a copywriter says the job involves "writing diverse texts for the Internet and content for social networks." The posting offered a salary of 30,000 rubles a month (then a little over $500) and said experience was unnecessary. Recruits would work with a team of "young and enthusiastic colleagues" in "a comfortable and stylish office," according to the posting.
That's not how Ludmila Savchuk remembers IRA, where she worked for two months in 2015. She told CNN a card system restricted access to other floors and employees were always under camera surveillance.
"Employees are not really allowed to talk to each other," she said.
Savchuk says she estimates that now "there are about 1,000 people working at Savushkina Street. And this is just one building." She believes other employees work remotely.
Another former employee, interviewed anonymously by the independent Russian TV network RAIN this week, said: "There was a goal -- to influence opinions, to lead to a discussion. ... There was a strategy document. It was necessary to know all the main problems of the United States of America. Tax problems, the problem of gays, sexual minorities, weapons."
The former employee said the mission was to "get into the dispute yourself to fire it up, try to rock the boat." He gave an example: "It was necessary to write that sodomy is a sin. This would always get you a couple of dozen likes."
He said IRA made its employees watch the US TV series "House of Cards" to improve their English.
Not unlike the fictional White House of Frank Underwood, Savchuk says, "The atmosphere there reminded me of some anti-utopian Gulag."