One is known as "General Armageddon," the other as "Putin's chef." Both have a checkered past and a reputation for brutality. One launched the insurrection, the other reportedly knew about it in advance. And right now, both are nowhere to be found.

The commander of the Russian air force Sergey Surovikin and the Wagner chief Yevgeny Prigozhin have not been seen in public in days as questions swirl about the role Surovikin may have played in Prigozhin's short-lived mutiny.

Kremlin has remained silent on the topic, embarking instead on an aggressive campaign to reassert the authority of the Russian President Vladimir Putin.

Here's what we know about the two men in the spotlight.

What is happening?

On Wednesday, the Russian-language version of the independent Moscow Times cited two anonymous defense sources as saying that Surovikin had been arrested in relation to the failed mutiny. CNN has been unable to independently verify that claim.

A popular blogger going by the name Rybar noted on Wednesday that "Surovikin has not been seen since Saturday" and said nobody knew for certain where he was. "There is a version that he is under interrogation," he added.

A well-known Russian journalist Alexey Venediktov -- former editor of the now-shuttered Echo of Moscow radio station -- also claimed Wednesday Surovikin had not been in contact with his family for three days.

But other Russian commentators suggested the general was not in custody. A former Russian member of Parliament Sergey Markov said on Telegram that Surovikin had attended a meeting in Rostov on Thursday, but did not say how he knew this.

"The rumors about the arrest of Surovikin are dispersing the topic of rebellion in order to promote political instability in Russia," he said.

Adding further to the speculation, Russian Telegram channel Baza has posted what it says is a brief interview with Surovikin's daughter, in which she claimed to be in contact with her father and insists that he has not been detained. CNN cannot confirm the authenticity of the recording.

Why is everyone talking about Surovikin?

Surovikin has been the subject of intense speculation over his role in the mutiny after the New York Times reported on Wednesday that the general "had advance knowledge of Yevgeny Prigozhin's plans to rebel against Russia's military leadership." The paper cited US officials who it said were briefed on US intelligence.

Surovikin released a video Friday, just as the rebellion was starting, appealing to Prigozhin to halt the mutiny soon after it began. The video message made it clear he sided with Putin. But the footage raised more questions than answers about Surovikin's whereabouts and his state of mind -- he appeared unshaven and with a halting delivery, as if reading from a script.

Asked about the New York Times story, Kremlin spokesperson Dmitry Peskov said: "There will be now a lot of speculation and rumors surrounding these events. I believe this is just another example of it."

One European intelligence official told CNN there were indications that top Russian security officials had some knowledge of Prigozhin's plans, and may not have passed on information about them, preferring instead to see how they played out.

"They might have known, and might have not told about it, [or] known about it and decided to help it succeed. There are some hints. There might have been prior knowledge," the official said.

Documents shared exclusively with CNN suggest that Surovikin was a VIP member of the Wagner private military company. The documents, obtained by the Russian investigative Dossier Center, showed that Surovikin had a personal registration number with Wagner. Surovikin is listed along with at least 30 other senior Russian military and intelligence officials, whom the Dossier Center says are also VIP Wagner members.

It is unclear what Wagner's VIP membership entails, including whether there is a financial benefit. Wagner has not answered CNN's request for a response.

And what about Prigozhin?

Prigozhin meanwhile, played the central role in the short-lived insurrection -- it was he who ordered Wagner troops to take over two military bases and then march on Moscow.

Why he did so depends on who you ask.

The Wagner chief himself claimed the whole thing was a protest, rather than a real attempt to topple the government. In a voice message released Monday, he explained the "purpose of the march was to prevent the destruction of PMC Wagner." The comment seemed to be a reference to a statement by the Russian Ministry of Defense that it would employ Wagner's contractors directly, essentially forcing Prigozhin's lucrative operations to shutter.

He also said he wanted to "bring to justice those who, through their unprofessional actions, made a huge number of mistakes during the special military operation," referring to Russia's war on Ukraine with the Kremlin-preferred term "special military operation."

It is clear the Kremlin sees the events of last weekend differently. Putin assembled Russian security personnel in Moscow Tuesday, telling them they "virtually stopped a civil war" in responding to the insurrection.

The Wall Street Journal reported Wednesday that Western officials believe Prigozhin planned to capture Defense Minister Sergei Shoigu and top army general Valery Gerasimov. When asked about the WSJ report, two European security sources told CNN that while it was likely Prigozhin would have expressed a desire to capture Russian military leaders, there was no assessment as to whether he had a credible plan to do so.

Where are they now?

Nobody knows. Prigozhin was last spotted leaving the southern Russian city of Rostov-on-Don Saturday, after abruptly calling off his troops' march on Moscow.

He released an audio message Monday, explaining his decision to turn his troops back. The Kremlin and the Belarusian President Alexander Lukashenko claimed on Saturday that Prigozhin agreed to leave Russia for Belarus.

Lukashenko said he brokered a deal that would see Prigozhin exiled in Belarus without facing criminal charges. According to Lukashenko, the Wagner chief arrived in Belarus Tuesday. While there are no videos or photos showing Prigozhin in Belarus, satellite imagery of an airbase outside Minsk showed two planes linked to Prigozhin landed there on Tuesday morning.

As for Surovikin, the commander of the Russian air force has not been seen in public since overnight on Friday when he issued the video.

What is the Kremlin saying?

Not much. CNN has reached out to the Kremlin and Russian Ministry of Defense for comment on Surovikin's whereabouts. The Kremlin said on Wednesday, "no comment," and a defense ministry spokesperson said: "I can't say anything."

When questioned whether Putin continued to trust Surovikin, Peskov said during his daily phone call with reporters: "He [Putin] is the supreme commander-in-chief and he works with the defense minister, [and] with the chief of the General Staff. As for the structural divisions within the ministry, I would ask you to contact the [Defense] Ministry."

Peskov also told journalists that he did not have information about the whereabouts of Wagner boss Yevgeny Prigozhin.

One Russian official has said that Surovikin is not being held in a pre-trial detention center in Moscow, as some independent media and blogs have suggested.

"He is not in Lefortovo or any other pre-trial detention facility. I don't even want to comment on the nonsense about "an underground detention facility in Serebryany Bor," Alexei Melnikov, executive secretary of the Public Monitoring Commission in Russia, said on his Telegram channel.

The Lefortovo facility is where suspects accused of espionage or other crimes against the state are often held.

What else is known about the pair?

Prigozhin was once a close ally of Putin. Both grew up in St. Petersburg and have known each other since the 1990s. Prigozhin made millions by winning lucrative catering contracts with the Kremlin, earning him the moniker "Putin's chef."

He then cast his net wider, becoming a shadowy figure tasked with advancing Putin's foreign policy goals. He bankrolled the notorious troll farm that the US government sanctioned for interference in the 2016 US presidential election; created a substantial mercenary force that played a key role in conflicts from Ukraine's Donbas region to the Syrian civil war; and helped Moscow make a play for influence on the African continent.

He gained notoriety after Russia launched its full-scale war on Ukraine in February 2022. The private military chief seemingly built influence with Putin over the course of the conflict, with his Wagner forces taking a leading role in the labored but ultimately successful assault on Bakhmut earlier this year. The capture of that city was a rare Russian gain in Ukraine in recent months, boosting Prigozhin's profile further.

His forces are known for their brutal tactics and little regard for human life and have been accused of several war crimes and other atrocities. Several former Wagner fighters have spoken of the brutality of the force. Prigozhin himself has previously told CNN that Wagner was an "exemplary military organization that complies with all the necessary laws and rules of modern wars."

Using his new-found fame, Prigozhin criticized Russia's military leadership and its handling of the war in Ukraine -- with few consequences. But he crossed numerous red lines with Putin over the weekend.

Surovikin is known in Russia as "General Armageddon," a reference to his alleged brutality.

He first served in Afghanistan in the 1980s before commanding a unit in the Second Chechen War ​in 2004.

That year, according to Russian media accounts and at least two think tanks, he berated a subordinate so severely that the subordinate took his own life.

A book by the Washington DC-based Jamestown Foundation, a think tank, said that during the unsuccessful coup attempt against former Soviet President Mikhail Gorbachev in August 1991, soldiers under Surovikin's command killed three protesters, leading to Surovikin spending at least six months in prison.

As the Commander-in-Chief of the Russian Aerospace Forces during Russia's operations in Syria, he oversaw Russian combat aircraft causing widespread devastation in rebel-held areas.

In a 2020 report, Human Rights Watch named him as "someone who may bear ​command responsibility" for the dozens of air and ground attacks on civilian objects and infrastructure in violation of the laws of war​" during the 2019-2020 Idlib offensive in Syria. ​

The attacks killed at least 1,600 ​civilians and forced the displacement of an estimated 1.4 million people, according to HRW​​, which cites UN figures.

Where does this leave Putin?

The general consensus among western officials and analysts is clear: in his entire 23 years in power, the Russian president has never looked weaker.

US President Joe Biden told CNN on Wednesday that Putin has "absolutely" been weakened by the short-lived mutiny and said Putin was "clearly losing the war."

The European Union's High Representative for Foreign Affairs said the Wagner rebellion showed Putin was "not the only master in town" and "has lost the monopoly of force."

Speaking to journalists in Brussels on Thursday, Josep Borrell cautioned that the global community has to be "very much aware of the consequences" adding that "a weaker Putin is a greater danger."

As for his domestic image, Putin appears to have embarked on a charm offensive, trying to reassert his authority.

He has attended an unusually high number of meetings in the past few days and was even seen greeting members of public. That is a stark reversal of tactic. Putin has stayed in near-seclusion for the past three years.

On Wednesday though, he flew for an official visit to Dagestan, meeting local officials and supporters in the streets of the city of Derbent, according to video posted by the Kremlin. On Thursday, he attended -- once again in person -- a business event in Moscow.