When police found Mikhail Lesin dead in a Washington, D.C., hotel room, the most interesting question wasn’t the cause of his demise, but what he was doing in the United States in the first place.

The former propaganda chief for Russian president Vladimir Putin, nicknamed “the bulldozer” for his history of rolling over his opposition, Lesin had been under scrutiny by the FBI and the Justice Department for potential money laundering and violation of corruption laws. Lesin was suspected of hiding ill-gotten gains in nearly $30 million worth of luxury real estate in southern California, an astounding set of assets for a man supposedly collecting a civil servant’s salary. He’d also been considered for sanctions that would have prevented him from obtaining a visa to enter the United States.

Sen. Roger Wicker, a Republican from Mississippi who has spent years looking into corruption and human-rights abuses in Russia, had asked the Justice Department to investigate Lesin. In December 2014, the department confirmed it had referred Lesin’s case to the Criminal Division and to the FBI. While officials declined to say whether they formally opened an investigation, several close watchers of Lesin’s case told The Daily Beast they thought it was all but certain that he was being pursued by U.S. law enforcement. And if he wasn’t under active criminal investigation, the FBI had enough evidence to consider opening a case, they said. A bureau spokesperson declined to comment on the matter.

So why did Lesin, who was 57, tempt fate by entering the United States this past November?

The purpose of his visit was never made clear. But he was staying in a mid-range hotel on Washington’s DuPont Circle. While not shabby, it’s doesn’t seem the kind of place that attracts people who buy multimillion-dollar estates. It does, though, offer a comparatively low per-night rate, perhaps more in line with U.S. government budgets, and is known to host foreign government officials and visitors on exchange programs. It’s also located a short drive from FBI and Justice Department headquarters.

These are the broad strokes of Lesin’s case. And in some foreign policy circles in Washington—as well as in Russian media—they have fueled speculation that Lesin was murdered after coming to Washington to cut a deal with the FBI.

Lesin certainly would have had a lot to say about Putin’s inner circle—he worked with, and reportedly owed money to, some of the most powerful men in Russian media and finance. And he would have had a powerful incentive to cooperate with U.S. authorities, namely hanging onto his several mansions in Los Angeles, which potentially could have been seized. At least two of the homes are known to be occupied, respectively, by his daughter and his son, a Hollywood film producer whose star is on the rise.

Adding to the mystery, the precise cause of Lesin’s untimely demise hasn’t been revealed. Almost immediately, the broadcasting outfit RT (Russia Today), widely seen as a Kremlin mouthpiece, reported that Lesin died of a “heart attack,” citing an unnamed “family member.”

But a spokesperson for the Washington, D.C., police department told The Daily Beast that Lesin’s death is still under investigation. And although a coroner performed an autopsy nearly two months ago, the police aren’t saying how he died. That’s an unusually long time not to publicly state a cause of death.

The conspiracy theories are arguably well-founded, because it wouldn’t be the first time someone who posed a political threat to Putin wound up dead under unusual circumstances, including poisoning.

Lesin was also being squeezed by the U.S. government. Two years ago he’d been nominated by human-rights groups for the so-called Magnitsky list of Russian human-rights violators, which would have allowed Washington to deny him a visa and seize his assets in this country. Lesin was not placed on the public list, which consists mainly of mid-level officials not as influential as the former propaganda chief. But U.S. officials maintain a classified annex which reportedly includes more senior Russians, including those closer to Putin. It’s not known whether Lesin was on that list, but activists lobbied hard to put him there.

He would have been an ideal candidate. Not only was he one of RT’s founding fathers, credited with conceiving of the network while working for Putin in order to counter what he saw as anti-Russia journalism in the West. (“It’s been a long time since I was scared by the word propaganda,” Lesin said in 2007, according to RT. “We need to promote Russia internationally. Otherwise, we’d just look like roaring bears on the prowl.”)

Lesin was also a longtime Putin crony, and he played a central role in an early project by the Russian strongman to gut the country’s independent television station, NTV, which had aired critical reports about government corruption, the war in Chechnya, and had become a soapbox for prominent Putin critics. While Lesin was serving as the information minister, Russia jailed NTV’s founder and majority shareholder, Vladimir Gusinsky.

“While he was there, the information minister made an offer: Gusinsky could have his freedom if he agreed to transfer his media holdings to Gazprom, the state-owned energy monopoly,” according to Russian journalist Vladimir Kara-Muzra, who has probed Lesin’s financial and real estate holdings. It was a naked power play that the European Court of Human Rights found was politically motivated and amounted to state-sanctioned blackmail.

Gusinksy didn't end up going along with the deal to hand over the media company. But Gazprom took over NTV anyway--by force--and in 2013 Lesin became the head of Gazprom-Media, an actual state-run media organization. RT, which reported the cause of Lesin’s death before a medical examiner had even seen his body, merely receives funding from the state.

The Gazprom takeover has raised concerns among U.S. investigators that Lesin may have come by a fortune through illegal seizures of private property, and then laundered those proceeds by stashing them in American real estate, according to two sources who have followed Lesin’s finances and asked not to be identified.

Landing Lesin could have led investigators to other, even bigger fish. As Wicker wrote to then-Attorney General Eric Holder in 2014, Lesin “may also have close business ties with individuals subject to U.S. sanctions,” as well as organizations, including Bank Rossiya, which is closely linked to Gazprom, and the bank’s owner, Yury Kovalchuk, a billionaire who ranks among Russia’s richest people, is reportedly close to Putin personally, and was sanctioned by the Treasury Department after Russia invaded Crimea.

If Lesin were found to be violating U.S. money-laundering laws, it could provide a rare opportunity to snare a senior Putin aide. After Wicker pressed the issue, relying in part on public property records that clearly linked the L.A. mansions to Lesin, the Justice Department considered whether to go after him.

Following the news of his death, the Kremlin issued a statement on behalf of Putin, noting “The president has a high appreciation for Mikhail Lesin’s massive contribution to the creation of modern Russian mass media.”

But having Lesin as an informant would been a big contribution to U.S. law enforcement and intelligence. And the information that Wicker and his staff, as well as human-rights groups and journalists, dug up on Lesin may have pushed him closer to the FBI’s arms.

About two weeks after the Justice Department informed Wicker that the allegations against Lesin were referred to the FBI, Lesin resigned as the head of Gazprom-Media, citing unspecified “family reasons.” Kara-Murza, the journalist and Putin critic, who himself fell mysteriously ill last summer, has directly linked the department’s announcement to Lesin’s stepping down and said it showed that the threat of sanctions and prosecution could be used to bring down corrupt Russian officials.

“That’s just one example of how effective this process can be if it’s applied properly, if it’s done against the right people,” Kara-Murza said in remarks at the American Enterprise Institute, a Washington think tank, in October. Kara-Murza declined to discuss Lesin’s case with The Daily Beast, citing the Latin admonition “de mortuis nihil nisi bonum.” Of the dead, [say] nothing, unless good. “And I have nothing good to say about him.”

Meanwhile, Lesin’s children have also kept mum. His son, Anton Lessine (the surnames are spelled differently), didn’t respond to a request for comment, and his daughter couldn’t be reached. Anton has been on a roll in Hollywood, helping financing high-profile movies with A-list talent. He was the executive producer of the Arnold Schwarzenegger action vehicle Sabotage, the Brad Pitt WWII tank pic Fury, 2015’s Bill Murray comedy Rock the Kasbah, and 2016’s transgenerational buddy flick Dirty Grandpa, starring Robert DeNiro and Zac Effron.

Times are good for the son of the ex-Putin aide, who seems to have come out of nowhere in the famously hard-to-crack world of big-budget filmmaking. He recently purchased a mansion in L.A.’s Pacific Palisades for an asking price of nearly $4 million. How exactly the Lesin family came into such good fortune is a question that has piqued the interest of U.S. investigators.

As might another question: Was Lesin in debt, and ready to flee Russia for a new life? After Lesin’s death, The Moscow Times reported that he may have stepped down from Gazprom-Media after losing an internal power struggle. Jobless and with high-level enemies, Lesin also owed “a huge amount of money” to Kovalchuk, the billionaire banker, which he didn’t intended to repay, the news organization reported, citing anonymous sources.

“He also underestimated his rivals,” The Moscow Times wrote. “The heads of three of Russia's major TV channels complained to President Putin that Lesin had begun behaving as if he was their boss, as he had been while press minister.”

The walls were closing in on Lesin--in Washington and in Moscow. Perhaps Lesin’s trip to that DuPont Circle hotel was his first step towards a new life. But if he’d become an enemy of Putin and his friends, even the FBI might not have been able to save him.