Updated

A security aide to businessman Yevgeny Prigozhin, who has been indicted by American investigators for allegedly trying to interfere with the 2016 U.S. election, says the Russian mogul has been involved in attacks on several people and at least one killing, an independent Russian newspaper reported Monday.

Prigozhin has been dubbed "Putin's chef" for organizing catering events for Russian President Vladimir Putin and even personally serving him and his guests on some occasions.

The Novaya Gazeta article by Denis Korotkov that was published Monday came out several days after unknown people sent a funeral wreath to the journalist's home and left a basket with a severed goat's head at the newspaper's office.

Korotkov's article relies on several interviews with Valery Alemchenko, a former convict who worked for Prigozhin, who said he orchestrated attacks on Prigozhin's opponents as well as the killing of an opposition blogger in Russia's north-west at the mogul's behalf.

U.S. authorities on Friday brought charges against another Prigozhin employee, bookkeeper Elena Khusyaynova for helping oversee the finances at a so-called troll farm that aimed to influence U.S. politics through social media postings. When reached by phone on Monday morning, the woman's ex-husband, Ravil Khusyaynova, told The Associated that she refuses to speak to the media.

Amelchenko also said several people working for Prigozhin had traveled to Syria last year to test an unknown poison on Syrians who refused to fight for Syrian President Bashar Assad's government. Novaya Gazeta corroborated the account with two other sources.

Amelchenko disappeared early this month shortly after meeting the reporter and is now on a Russian police list of missing persons.

Another member of Prigozhin's security detail, Oleg Simonov, who is suspected of attacking the husband of an opposition activist and injecting him with poison, died last year under murky circumstances.

In addition, the activities of Prigozhin's private security contracting firm Wagner have been well-documented. The AP last year published a memorandum discussing an oil deal between Prigozhin's company and the Syrian government.