Retired US general Robert Adams said Prigozhin was either killed or imprisoned for having led Wagner’s failed coup.SERGEI ILNITSKY/POOL/AFP via Getty Images

A retired US general said Wagner Group leader Yevgeny Prigozhin is either dead or imprisoned in one of Russia's gulags after his failed mutiny.

Former US Forces Korea commander Gen. Robert Adams (Ret.) told ABC News the renegade mercenary boss was likely erased either way. "I think he'll either be put in hiding or sent to prison or dealt with some other way, but I doubt we'll ever see him again," he said.

Prigozhin was one of Putin's trusted allies in Russia's invasion of Ukraine. However, late last June, the mercenary group controlled the southern Russian city of Rostov-on-Don for almost 24 hours and was about to march to Moscow in an apparent mutiny or rebellion until it was called off at the last minute.

As a result, Prigozhin exiled himself to Belarus at the invitation of its president, Alexander Lukashenko. A few days later, the Belarusian president said Prigozhin reportedly met with Russian president Vladimir Putin, which some speculated to be "highly staged". Nothing was heard about the Wagner boss ever since.

"I'd be surprised if we actually see proof of life that Putin met Prigozhin," Adams added.

Prigozhin's Fate, Whereabouts Unknown

From the onset, Wagner leaders and Russian military commanders have been at odds with each other in their invasion of Ukraine. This came to a head when Prigozhin released a Telegram video showing dead Wagner troops. In the video, he accused Russian defense minister Sergei Shoigu and Russian chief of defense staff Valery Gerasimov, of not providing ammunition for Wagner mercenaries.

After the failed rebellion, Putin gave Wagner troops the choice to either be incorporated into the Russian military or accompany Prigozhin to Belarus. Those who chose to stay with the boss established their facility at an abandoned Belarusian base near Minsk. All charges against Prigozhin were also dropped to allow him to move to Belarus.

Sources claim Prigozhin remains in Russia for stomach cancer treatment, but the announcement was seen as suspicious enough for some to say he was being erased by the Kremlin and his contractors are being transitioned into regular Russian Army soldiers.

Earlier, Wagner troops were reported to have surrendered their weapons to the Russian military.

Anti-Putin Russian outlet Proekt originally cited claims from Prigozhin's former employees saying he had undergone cancer treatment and his failed march to Moscow was a gamble made by a man with little or nothing to lose.