WASHINGTON — Long before the political data firm he oversees, Cambridge Analytica, helped Donald Trump become president, Nigel Oakes tried a very different form of influencing human behavior. It was called “marketing aromatics,” or the use of smells to make consumers spend more money.

In the decades since, the Eton-educated British businessman has styled himself as an expert on a wide variety of “mind-bending” techniques — from scents to psychological warfare to campaign politics.

But some 25 years after his foray into aromatics, a bad odor has arisen around his use of data to influence voter behavior. Oakes and his partners, who include Cambridge Analytica CEO Alexander Nix, are under intense scrutiny over their methods in the 2016 campaign, including the alleged improper use of Facebook data. Some news reports have also found links to Russia that the company has downplayed.

Oakes and the company he co-founded in 2005 along with Nix, SCL Group, have now drawn the interest of congressional officials. Three Republican senators wrote Oakes a letter this week requesting information and a briefing related to Facebook’s sudden suspension last Friday of Cambridge Analytica, which is a closely affiliated subsidiary of SCL.

Data analytics experts described Oakes as a hidden hand running both SCL and Cambridge Analytica.

The request — from Senate commerce committee members John Thune (R-S.D.), Roger Wicker (R-Miss.) and Jerry Moran, (R-Kan.) — came after recent allegations that Cambridge Analytica used inappropriately harvested private Facebook data on nearly 50 million users and exploited the information to assist President Donald Trump’s 2016 campaign.

But that has triggered wider questions about whether Cambridge Analytica, whose board once included former Trump political strategist Steve Bannon, could have played some role in the Kremlin’s scheme to manipulate U.S. social media in 2016. The company denies that.

Captured on an undercover video by Britain’s Channel 4 News, Nix boasted that the firm “did all the research, all the data, all the analytics, all the targeting,” for the Trump campaign, adding that “our data informed all the strategy.” (Trump officials call that an exaggeration.)

Adding to the concern is the role of Aleksandr Kogan, a Russian-born researcher at Cambridge University who collected the Facebook data without disclosing that it would be used commercially, and who was also working for a university in St. Petersburg, Russia at the time. Cambridge Analytica also reportedly discussed a business relationship in 2014 and 2015 with the the Kremlin-connected Russian oil giant Lukoil, which expressed interest in how data is used to target American voters, according to the New York Times.

The recent flurry of coverage has barely mentioned the 55-year-old Oakes, a virtual unknown in the U.S. but more familiar in Great Britain, in part because of his relationship in the 1990s with a member of the royal Windsor family.

But data analytics experts described Oakes as a hidden hand running both SCL and Cambridge Analytica.

“Anyone right now that is focusing on the problems with Cambridge Analytica should be backtracking to the source, which is Nigel Oakes,” said Sam Woolley, research director of the Digital Intelligence Lab at the Silicon Valley-based Institute for the Future.

“My research has shown that Cambridge Analytica is the tip of the iceberg of Nigel Oakes’ empire of psyops and information ops around the world,” said Woolley, whose research aims to help protect democracy from the nefarious use of rapidly evolving communications technology. “As you start to dig in to that, you find out a lot of very concerning things.”

Woolley said he attended a Cambridge Analytica “meet-up” in April 2016 during the New York presidential primary in New York. At the time, the company was working for another candidate, Senator Ted Cruz (R-Texas), and gave a wide-ranging overview of their activities, Woolley said.

It was clear from the session that the two companies are completely intertwined, Woolley said. He recalled that Cambridge Analytica leaders “conflated all of their work with SCL’s work,” including in several overseas elections. Based on his ongoing research, he described the two firms as selling “political marketing to the highest bidder, whether you’re in government, the military or politics, even authoritarian” regimes.

Oakes and SCL Group did not return calls seeking comment through a spokesperson.

"We use the same techniques as Aristotle and Hitler,” he told an interviewer in 1992. “We appeal to people on an emotional level to get them to agree on a functional level."

SCL Group — like its predecessor, Strategic Communication Laboratories, which Oakes co-founded in 1993 — is no stranger to controversies related to foreign elections, including in connection with alleged dirty tricks it has allegedly employed on behalf of political clients from Europe to Africa and Asia.

The company also made headlines in 2005 when it billed itself at a global arms fair in London as the first private company to provide psychological warfare services, or "psyops," to the British military.

At the time, Oakes, as chief executive, said he was confident that psyops could shorten military conflicts, and that governments would buy such a service, which SCL had provided commercially.

“We used to be in the business of mind bending for political purposes,” he told a reporter, “but now we are in the business of saving lives."

Those who know Oakes, or know of him, are somewhat skeptical.

One private investigator said the company is known to have done extensive work for the U.S. military and other government agencies against targets including Iran. SCL got its start in the U.S. by selling the same psychological warfare product as it did to the British, including manipulation of elections and “perception management,” or the intentional spread of fake news.

The State Department confirmed to Defense One this week that it retains SCL Group on a contract to "provide research and analytical support in connection with our mission to counter terrorist propaganda and disinformation overseas."

Company literature describes some of SCL's services, besides "psychological warfare," as "influence operations" and "public diplomacy.”

Absent from such descriptions is some of the more bombastic rhetoric of Oakes’ youth.

"We use the same techniques as Aristotle and Hitler,” he told an interviewer in 1992. “We appeal to people on an emotional level to get them to agree on a functional level."

On its website, SCL Group does not highlight its connections to Cambridge Analytica.

“Our vision is to be the premier provider of data analytics and strategy for behavior change,” the website says.

“Our mission is to create behavior change through research, data, analytics, and strategy for both domestic and international government clients.”

But Oakes and his company have a history of secrecy, making the hidden-camera footage of Nix all the more shocking. In the footage aired by Channel 4, Nix appears to tell a journalist posing as a potential client that the company could, for instance, send Ukrainian sex workers to an opponent’s house to sabotage him.

SCL Group said it has suspended Nix while it investigates, and several U.S. lawmakers cited the reports in saying that they want to call him back before committees investigating Russian meddling to answer more questions.

One British journalist who has investigated the two companies and their leaders also suggested that the real trail of questions leads to Oakes.

“Alexander Nix has been suspended from a shell company that has no employees and no assets,” said Carole Cadwalladr of the Observer, who authored last weekend’s expose, and others. “If you think this ends here, think again.”

The letter from the three senators — which they also sent to Facebook CEO Mark Zuckerberg — asks Oakes whether he acknowledges the conduct described in Facebook's statement announcing the suspension of Nix’s account, and those of both SCL Group and Cambridge Analytica.

“We ought to bring Alexander Nix back and quite frankly the other Cambridge Analytica witnesses that had been on our witness list. Still a lot of questions" — Adam Schiff

It also asks him to provide information about whether he was aware of other activity by Cambridge that Facebook said led to the suspension, including how it accessed the data in question and whether it falsely certified that it had destroyed it at Facebook's request.

“Consumers rely on app developers to be transparent and truthful in their terms of service so consumers can make informed decisions about whether to consent to the sharing and use of their data,” the senators wrote. “Therefore, the allegation that SCL was not forthcoming with Facebook or transparent with consumers is troubling.”

The senators reminded Oakes that their committee has jurisdiction over the internet and communications technologies generally, as well as over consumer protection and data privacy issues.

Meanwhile, Democrats who have been investigating Russian election interference and suspected collusion between the Kremlin and the Trump campaign are expressing heightened interest in Oakes’s company, though for how their focus is primarily on Nix.

Representative Adam Schiff, the top Democrat on the House intelligence committee, said on MSNBC Wednesday that he was particularly concerned about Nix’ comments, captured by Channel 4, about how he got off easy during his interview with Congress.

“The Republicans asked three questions. Five minutes, done,” Nix said. And while the Democrats asked two hours of questions, Nix said he didn’t have to answer them because “it’s voluntary.”

Schiff (D-Calif.) said Wednesday he wants Nix to come back and testify as well as witnesses the committee Democrats wanted to interview.

“We didn’t get the information that we needed and in light of these whistleblower allegations there are serious questions about the truthfulness of Mr. Nix’s testimony,” Schiff said.

“We ought to bring Alexander Nix back and quite frankly the other Cambridge Analytica witnesses that had been on our witness list. Still a lot of questions.”