Wagner mercenary chief Yevgeny Prigozhin is reportedly sequestered in a windowless room following his abandoned march on Moscow, amid fears he will fall victim to a "mysterious" death like others who have angered Vladimir Putin.

Speaking to MSNBC, the US Senate intelligence committee chair Mark Warner said a move by Prigozhin to mitigate a potential assassination attempt showed where his relationship with the Russian president stood.

"I understand, literally as I was coming on air, he says he's in Minsk and actually is – get this – there are reports he is in one of the only hotels in Minsk that doesn't have any windows," Warner said.

"I say that because – again this has been in public reporting there have been a number of Russian entity individuals who have run afoul of Putin over the last year and a half who have mysterious fallen out of fifth, sixth, seventh floor windows so if he is in Minsk in a hotel with no windows, that would show at least what his mindset is in terms of how his relationships are with Putin at this point."

Senate Intelligence Committee Chair Mark Warner (D-VA) says there are reports Wagner Group leader Yevgeny Prigozhin is staying in a Minsk hotel with no windows:

“That would show at least what his mindset is in terms of how his relationships are with Putin at this point.” pic.twitter.com/WeGoArbrR2

— The Recount (@therecount) June 26, 2023

Prigozhin's rebellion against the Russian Ministry of Defence, which ended when his Wagner mercenaries and their convoy turned back from Moscow in order to avoid shedding "Russian blood", was described by Putin as "internal treason".

And while Russia's president did allow an exile deal brokered by Belarus’s Alexander Lukashenko, the uprising has left a chink in Putin's armour that he is unlikely to forget.

Speaking after the abandoned March on Moscow, Lukashenko told Belarusian state media that he had had to talk Putin out of "wiping out" Prigozhin.

"I suggested to Putin not to rush," Lukashenko said.

"'Come on,' I said, 'Let's talk with Prigozhin, with his commanders.'"

One advisor to Ukrainian prime minister Volodymyr Zelensky described the Russian president's loss of authority over the rebellion as marking the beginning of the end for Putin.

“I think the countdown has started,” said Andriy Yermak at a Kyiv briefing.

“What Ukraine has seen since 2014 has become evident for the entire world.

“This is a terrorist country whose leader is an inadequate person who has lost connection with reality. The world must conclude that it’s impossible to have any kind of serious relationship with that country.”

While Prigozhin may have found temporary respite in Minsk, Russia has a history of using deadly force to silence its dissenters, and in 2022 a number of Russian oligarchs who had angered the leadership died in what were widely viewed as mysterious circumstances.