Rinat Akhmetshin, a Russian-American lobbyist who has been accused of being a former Soviet intelligence officer, confirmed that he was also at the now infamous meeting Donald Trump Jr. took with a Russian lawyer.

Trump Jr. did not mention Akhmetshin’s presence at the meeting in previous public comments about it, but Akhmetshin confirmed he was there to The Associated Press.

His name has surfaced before involving Russian lobbying efforts to kill the Magnitsky Act, which also involved Russian lawyer Natalia Veselnitskaya and Fusion GPS, the firm of former journalists that solicited the Christopher Steele dossier against President Donald Trump. Fusion GPS denies any knowledge of the Trump Jr. meeting; a top Republican senator has filed a complaint alleging that Fusion GPS was really acting as an unregistered agent for Russia. The complaint also mentions Veselnitskaya and Akhmetshin, a controversial behind-the-scenes figure who was once accused of being involved in hacking and who also met with Republican U.S. Rep. Dana Rohrabacher.

The Magnitsky Act in the U.S. Congress was fought by a major Russian lobbying effort because it, Politico reported, “authorizes the president to freeze assets and deny visas to foreign officials responsible for corruption and human rights violations.” It was a priority of the Russian government to defeat.

Here’s what you need to know:

1. He’s Been Labeled a Former Soviet Intelligence Officer but Says He Wasn’t a Spy

The Magnitsky Act that Akhmetshin has been involved in trying to defeat in the U.S. Congress is also a top priority of the Russian government and Vladimir Putin, who want it killed. It’s a very complicated web, but the shorthand version is this: Akhmetshin was part of a group of Russians – and an American firm Fusion GPS (which was behind the salacious Steele dossier) – who were involved in lobbying efforts to defeat it.

That’s concerned U.S. Senator Chuck Grassley, the chair of the Senate Judiciary Committee, so much he filed a complaint with the Justice Department alleging that Fusion GPS should have registered as an agent of Russia because of the lobbying efforts it was involved in that also involved, among others, Veselnitskaya and Akhmetshin, both of whom were in the meeting with Trump Jr.

And it’s Akhmetshin’s background, allegedly in Russian intelligence (shorthand, as a Russian spy), that Grassley and an American company that also filed a complaint have used, in part, to allege that the lobbying efforts are really the work of Russia.

However, Akhmetshin denies he was a spy, telling the Associated Press that he was “part of a Soviet military unit that dealt with counterintelligence, but was never trained as a formal spy. According to NBC News, “Born in Russia, Akhmetshin served in the Soviet military and emigrated to the U.S., where he holds dual citizenship.”

Now here’s the longer version with documents:

In a complaint a company called Hermitage has filed with Justice about the lobbying efforts, Akhmetshin is described as follows: “Mr Akhmetshin is a former member of the Russian military intelligence services (GRU). He is now based in Washington DC as a lobbyist. He was previously hired by clients with the mandate to generate negative publicity. He was paid by a previous client to derail the US asylum application of a Russian citizen using false allegations of anti-Semitism.”

The Magnitsky Act was “named for a lawyer who suspiciously died in Russian custody after accusing Russian government officials and members of organized crime of using corporate identity theft against Hermitage Capital Management to fraudulently obtain and launder $230 million, some of which allegedly ended up in U.S. real estate projects. The Magnitsky Act imposed sanctions against those involved as well as other Russians designated as human rights abusers,” a statement previously released by Republican Senator Chuck Grassley says.

Hermitage’s CEO was a man named William Browder.

Veselnitskaya, the Russian lawyer who met with Donald Trump Jr., is named in a complaint filed by Browder with the Justice Department as “Natalia Veselnitskaya, the Russian lawyer for Prevezon.” Prevezon Holdings Limited, is defined as a Russian owned Cyprus registered company attempting to defeat the Magnitsky Act. According to the Browder complaint, Prevezon is “controlled/directed/influenced by the Russian Government in respect of the lobbying activity.” Trump Jr.’s own emails, which he dumped on Twitter July 11, allege he was told that Veselnitskaya was a government lawyer, but his father denies she was one.

According to the Daily Beast, Browder will brief the Senate Judiciary Committee in mid July about “the lawyer Natalia Veselnitskaya’s ties to the Russian government—including to former top members of the GRU and the FSB, two of the Kremlin’s main intelligence agencies.” Veselnitskaya has denied being an agent of the Russian government.

The Browder complaint further describes Veselnitskaya by saying she “is the lawyer to Prevezon and the Katsyv family,” adding that she “played a key role in organizing screenings of the film intended to rewrite the history of Sergei Magnitsky.” She also attended a House Foreign Affairs Committee hearing on U.S. policy towards Putin’s Russia, the complaint says. It also says that she then filed a report with Congress accusing the Magnitsky Act of being “based on lies.”

That film was an effort by the Russians to convince people in Washington that the Magnitsky Act was bad.

The complaint alleges that Glenn Simpson of Fusion GPS “has been hired by Prevezon to lobby for the anti-Magnitsky campaign.” The complaint says that Vladimir Putin made it his “primary foreign policy objective” to get the Magnitsky Act defeated and adds that Prevezon is owned by a man named Denis Katsyv.

According to a news release from Grassley, “Fusion GPS was reportedly tasked with generating negative press coverage of Browder and Hermitage.” Grassley alleged that Fusion GPS should have “registered as foreign agents under the Foreign Agent Registration Act (FARA).” He alleged to the Justice Department that “Fusion GPS reportedly ‘dug up dirt’ on Mr. Browder’s property and finances, and attempted to generate negative stories about Mr. Browder and Hermitage in the media, shopping stories to a number of reporters.”

Grassley also alleged that Fusion GPS was working with Rinat Akhmetshin, “a Russian immigrant to the U.S. who has admitted having been a ‘Soviet counterintelligence officer.'” Grassley wrote the Justice Department: “Fusion GPS is the company behind the creation of the unsubstantiated dossier alleging a conspiracy between President Trump and Russia. It is highly troubling that Fusion GPS appears to have been working with someone with ties to Russian intelligence –let alone someone alleged to have conducted political disinformation campaigns– as part of a pro-Russia lobbying effort while also simultaneously overseeing the creation of the Trump/Russia dossier.”

Who is Katsyv?

A law firm named BakerHostetler represented Katsyv, who “owns a company that the Justice Department has accused of laundering money from a tax fraud that Magnitsky uncovered,” according to Politico.

According to The Washington Post, Denis’ father “Pyotr Katsyv, was vice premier and minister of transport of Moscow region from 2004 to 2012. Katsyv’s deputy minister was Alexander Mitusov, Veselnitskaya’s ex husband.”

A Politico story from December 2016 reported that “BakerHostetler hired a private research firm known as Fusion GPS led by Glenn Simpson, a former Wall Street Journal reporter. (The firm also discussed information with journalists about Trump and his associates’ ties to Russia.)”

According to The Washington Post, Fusion GPS “did work on a lawsuit that involved Veselnitskaya for more than two years.” The Post reports that “Fusion GPS has said that it was working for the law firm BakerHostetler, which was representing Prevezon, a Russian holding company based in Cyprus, in its defense against Justice Department allegations that Prevezon laundered money stolen in the fraud Magnitsky uncovered.” There’s no known evidence that the Fusion GPS dossier work and this was connected, according to The Post.

2. Akhmetshin Was Called a ‘Russian Gun For Hire’ & Says Veselnitskaya Had Documents Purportedly About Democrats at the Meeting

good piece from last year on Rinat Akhmetshin, who was also at Trump Jr. meeting https://t.co/Im9aTKaeCT — KevinGHall (@KevinGHall) July 14, 2017

In an exclusive interview with The Associated Press, Akhmetshin alleged that Veselnitskaya “brought with her a plastic folder with printed-out documents that detailed what she believed was the flow of illicit funds to the Democrats” and “presented the contents of the documents to the Trump associates and suggested that making the information public could help the campaign.” He alleged she said it “could be a good issue to expose how the DNC is accepting bad money,” but when pressed on evidence she said the Trump campaign would need to research it further and Trump Jr. “lost interest,” according to AP.

Akhmetshin told AP “he does not know if Veselnitskaya’s documents were provided by the Russian government.”

Akhmetshin is a fairly well known figure in lobbying circles in Washington D.C.

A profile story on Akhmetshin described him as “the man at the back of the room who for nearly 20 years has worked the shadowy corners of the Washington lobbying scene on behalf of businessmen and politicians from around the former Soviet Union.”

However, he’s run into controversies before.

According to Radio Free Europe, In 2011, “Akhmetshin was accused of helping to organize a smear campaign against former Russian Duma deputy Ashot Egiazaryan, who had sought political asylum in the United States in the face of criminal charges in Russia related to a business dispute.”

A lawsuit filed in U.S. federal court in Manhattan contained court filings in which “lawyers allege he was enlisted, along with another Washington public-relations company and private investigators, to help publish articles in a Jewish newspaper accusing the deputy of anti-Semitism,” reported Radio Free Europe.

Radio Free Europe dubbed Akhmetshin a Russian “gun for hire.”

He also met with Dana Rohrabacher, the site reported.

“Akhmetshin has paid at least one visit to Congress in connection with new human rights legislation that builds on the earlier Magnitsky Act. Along with Ron Dellums, a former U.S. congressman from California and longtime Washington lobbyist, Akhmetshin visited House member offices on May 17 to meet with Dana Rohrabacher, another California congressman viewed as one of the most sympathetic U.S. officials to Russian causes,” reported Radio Free Europe.

The Hill reported that Rohrabacher was also approached by Russians lobbying against the Magnitsky Act. “Rep. Dana Rohrabacher, a California Republican with a reputation as a Moscow ally in Congress, told The Hill the information he received in April 2016 came from the chief prosecutor in Moscow and painted an alternative picture of the Russian fraud case that led to the passage of anti-Russia legislation in Congress known as the Magnitsky Act.”

According to the Hill, Rohrabacher said, “I had a meeting with some people, government officials, and they were saying, ‘Would you be willing to accept material on the Magnitsky case from the prosecutors in Moscow? ‘And I said, ‘Sure, I’d be willing to look at it.'”

The Hill reported that the outreach to Trump Jr. was part of a broad lobbying effort against Magnitsky by Russians that also included “lobbying overtures to journalists, State Department officials and lawmakers and congressional staff from both parties.”

3. Akhmetshin Was Accused of Being Involved in an Illegal Hacking Effort

Radio Free Europe reported that Akhmetshin has been linked to many controversial efforts, including one that involved hacking claims.

“Barely registering in U.S. lobbying records, the 48-year-old Akhmetshin has been tied to efforts to bolster opponents of Kazakhstan’s ruling regime, discredit a fugitive former member of Russia’s parliament, and undermine a Russian-owned mining firm involved in a billion-dollar lawsuit with company information allegedly stolen by hackers,” the site reported.

In 2015, Courthouse News reported that Akhmetshin was accused in a lawsuit by a mining company in New York of being involved in an illegal hacking effort.

“A law firm and a man accused of being a former Soviet spy hacked into a mining company’s computers to get an upper hand in overseas litigation,” Courthouse News reported of the company’s claims.

Courthouse News reported that the IMR lawsuit says “Akhmetshin, once a Russian government official, has for at least the last decade worked as a lobbyist in Washington, D.C.” was “running a little-known think tank called the International Eurasian Institute for Economic and Political Research.

“The suit claims Akhmetshin has made a name for himself by developing relationships with reporters at Harper’s Magazine, The Wall Street Journal and The Huffington Post. He disseminated inside information to journalists in an effort to tarnish certain companies’ reputations, IMR alleges,” according to Courthouse News.

4. Akhmetshin Admits Being at the Trump Jr. Meeting

At first, NBC reported that there was “a Russian-American lobbyist who was a former Soviet counter-intelligence officer” at the Trump Jr. meeting with Veselnitskaya, which has plunged the president’s son into ongoing controversy.

Reuters reported that “NBC News did not identify the former intelligence officer, who it said had denied any current ties to Russian spy agencies but had served in the Soviet military. He has emigrated to the United States, where he holds dual citizenship.”

Akhmetshin then admitted he was that person to the AP.

The AP reported that Akhmetshin said the Trump Jr. meeting was “not substantive” and he “actually expected more serious” talk.

“I never thought this would be such a big deal to be honest,” he told AP.

AP added that a spokesman for Putin denied knowing anything about Akhmetshin.

5. Fusion GPS, Which Was Behind the Trump Dossier, Was Also Involved in the Anti-Magnitsky Lobbying Effort

Trump Jr. has claimed that he was originally told by music publicist Rob Goldstone that the meeting would involve information bad for Hillary Clinton but that, when it occurred, all Veselnitskaya wanted to talk about was the Magnitsy Act and Russian adoptions.

Defeating the act has long been a priority of a group of lobbyists and a research firm and lawyers deployed to defeat it. Sen. Chuck Grassley has accused Fusion GPS, which admits it was behind the Steele dossier, of being an unregistered Russian agent because of its work with the Russians lobbying against Magnitsky, including Akhmetshin and Veselnitskaya.

Fusion GPS is a research firm that was founded by a group of former Wall Street Journal reporters. An unidentified “Never Trump” Republican first funded the company’s research against Trump, but that funding dried up when he won the primary. Fusion GPS then sought out unidentified Democratic funding sources to continue the research and commissioned Steele, a former British spy, to research Trump, reported Vanity Fair. Steele then produced the now infamous dossier that contained unverified and shocking allegations against Trump that he has adamantly denied.

No evidence has been produced, though, connecting Akhmetshin to the dossier or Fusion GPS to the Trump Jr. meeting.