Putin's oldest ally was the mastermind behind the assassination of Wagner warlord Prigozhin, report says

• The Wagner Group boss' plane-crash death was an assassination, The Wall Street Journal reported.
• A close Putin ally drove the plan, with the death seen as suspicious by observers, it said.

The death of the mutinous Wagner warlord Yevgeny Prigozhin in a plane crash was an assassination masterminded by Nikolai Patrushev, a close friend of Russian President Vladimir Putin, The Wall Street Journal reported.

Western intelligence officials and a former Russian intelligence officer told The Journal that the Wagner Group boss' death in August was driven and approved by the 72-year-old.

Prigozhin, who led a short-lived uprising against Russia's Defense Ministry this year, died after his business jet went down in a fiery crash outside Moscow. At the time, Putin suggested a hand grenade had detonated on the plane.

In reality, the former Russian intelligence officer told the Journal, Patrushev gave orders to his assistant in August to design an operation that would kill Prigozhin.

A small bomb was put under the plane's wing during a delay when safety inspectors were looking at the aircraft, Western intelligence officials told The Journal.

Dmitry Peskov, a Kremlin spokesperson, told Reuters he would not comment on the story, adding: "Lately, unfortunately, The Wall Street Journal has been very fond of producing pulp fiction."

Patrushev, like Putin, was a spy with the KGB intelligence agency. He later became the head of its successor, the FSB. He's now the secretary of Russia's Security Council and is considered by some as a replacement option for Putin if anything happens to the president.

The Journal described Patrushev as "Putin's oldest ally and confidant," describing him as loyal to Putin and linked to the assassination of those who threatened Putin's power.

Patrushev, the report said, mostly goes unnoticed during public occasions and is often a figure in the background. But he yields enormous power.

He had told Putin since summer 2022 that Prigozhin was a threat because the Wagner Group gave him too much political and military power, the report said.

Putin ignored those warnings until Prigozhin called Putin in October 2022 to complain about not getting enough equipment, the former Russian intelligence officer said.

Prigozhin's relationship with Putin and Russia's military worsened: In June, Russia's Defense Ministry said fighters in groups such as Wagner had to sign official army contracts, drawing Prigozhin's ire.

In its rebellion, the Wagner Group took a Russian military headquarters in the city of Rostov-on-Don and started marching toward Moscow, taking down Russian planes and helicopters.

The uprising ended before it reached Moscow, with a peace deal that involved Prigozhin leaving Russia for its neighbor Belarus, a Russian ally.

Patrushev came up with that deal, which also allowed his men to go with him or fight in Russia's military, The Journal reported.

Prigozhin's death was widely seen as suspicious, as it took place two months after Prigozhin and the Wagner Group staged its rebellion. But Russia denied any involvement. The Journal's report is the first to say Patrushev was behind Prigozhin's death.

Hours after the crash, a European who was involved in intelligence gathering and had back-channel communications with the Kremlin asked one of its officials what happened, The Journal reported.

The official said: "He had to be removed."

Russian officials and Patrushev did not respond to The Journal's requests for comment. The Russian Embassy in the UK did not immediately respond to a request for comment from Business Insider.