LONDON—The Russian woman who held a secret meeting with a troika of President Trump’s top campaign staff is the chief orchestrator of Moscow’s efforts to overturn one of President Vladimir Putin’s most hated American interventions against his regime.

Natalia Veselnitskaya’s mission is to destroy the Magnitsky Act—a package of U.S. sanctions that targets corrupt Russian officials and their comrades.

She is alleged to have lured senior members of the Trump family into the meeting with a promise of compromising information about Hillary Clinton.

The 42-year-old Veselnitskaya is also lawyer to Denis Katsyv, who has paid out millions of dollars in the wake of money laundering cases brought by the authorities in the U.S. and Israel, while assets linked to him have been frozen in the Netherlands and Switzerland, as previously reported by The Daily Beast.

Some of the financial crime cases brought against Katsyv allege that his company profited from the $230 million fraud uncovered by Sergei Magnitsky, a lawyer who subsequently died under suspicious circumstances in Russian custody.

One of Katsyv’s companies, Martash Investment Holding, which is registered in Israel, had $8 million seized by the Israeli authorities after a separate money laundering probe. Seven million dollars was frozen in Switzerland after claims of links to Russia’s biggest ever tax fraud, which Magnitsky uncovered.

Denis Katsyv’s father, Pyotr, was the vice governor of the Moscow region between 2004 and 2012, and is now vice president of the state-run Russian Railways.

During Pyotr Katsyv’s time as minister of transport in Moscow, his son’s new transportation company suddenly became extremely successful. It was the biggest in the region by the time Denis Katsyv was 25, making him a very wealthy man.

Some of those who raised questions about an apparent conflict of interesthave ended up in Russian prisons.

The U.S. Department of Justice seized property in Manhattan and the Netherlands owned by Denis Katsyv worth $15 million, alleging that money stolen in the fraud uncovered by Magnitsky had been funneled into Katsyv’s Prevezon company, which is registered in Cyprus.

The case brought by U.S. Attorney Preet Bharara was unexpectedly settled out of court on the eve of the trial in May two months after Bharara was fired by Trump.

The agreement saw Prevezon pay the U.S. government $5.9 million, but the company did not accept any wrongdoing.

The Magnitsky Act, which was passed through Congress in 2012 and named in his honor, is the source of great personal animosity for Putin. “Passage of Magnitsky Act is an outrageous act,” he told a press conference days after President Obama signed it into law.

With Obama set to leave office in the summer of 2016, Veselnitskaya apparently set her sights on the long-shot Trump campaign as a possible to route to satisfying her masters back in Moscow. She went to Trump Tower for a meeting with Donald Trump Jr., Jared Kushner, and then-campaign chairman Paul Manafort on June 9, according to a report in The New York Times.

Veselnitskaya, who was formerly married to the deputy minister of transportation Alexander Mitusov, acknowledges that she was there to lobby against the Magnitsky Act. She said she also discussed Russia’s U.S. adoption ban, which was implemented by Putin in a petty act of tit-for-tat vengeance for the Magnitsky Act, which was hugely embarrassing for a president who wanted to conceal the scale of corruption within his Mafia state.

Trump Jr. has claimed in a statement that the meeting was predominantly focused on efforts to restore the adoption program.

Veselnitskaya was indeed involved in an NGO that was set up in February 2016 called the Human Rights Accountability Global Initiative Foundation, which called for the adoptions to restart. In an email seen by The Daily Beast, accreditation for a press conference was requested in her name to represent the charity.

But there was only one way that Putin would relent—no matter how many orphaned children were cut adrift—and that was if the Magnitsky Act was scrapped.

Veselnitskaya worked obsessively to overturn the law that sanctioned 44 Russians linked to Magnitsky. The lawyer was allegedly tortured and beaten to death after uncovering a huge fraud perpetrated against the Russian people when subsidiaries of William Browder’s Hermitage Capital Management were stolen in 2007 and used to defraud $230 million from the Russian taxpayer.

Veselnitskaya has helped orchestrate lobbying efforts against the law in Washington, she has promoted an anti-Magnitsky movie, and it now appears that she was attempting to persuade the Trump campaign to quash the anti-Russian sanctions—perhaps in exchange for information that would influence the election.

“In 2016, Natalia Veselnitskaya’s main life project was to overturn the Magnitsky Act and change the narrative of what happened to Sergei Magnitsky,” Browder told The Daily Beast. “Her interests and the interests of Vladimir Putin were completely aligned. Putin made overturning the Magnitsky Act his single largest foreign policy priority.”

Social media accounts in Veselnitskaya’s name show her vitriol toward Browder—a man who dedicated himself to exposing corruption in Putin’s Russia.

When a legal letter from Browder’s representatives prevented the anti-Magnitsky movie’s premiere at the European Parliament from taking place, she wrote on Facebook: “Browder spat on EU values and this will come back on him as a tsunami.”

An account set up in her name, with the name of her law firm, fired off around 50 tweets attacking Browder in 2015. There were none about the plight of the lost adoptees.

Veselnitskaya was initially refused entry to the United States when she applied for a visa for herself and her children for the end of 2015. According to court files, she said she was granted a temporary “parole letter” allowing her into the country to assist her client Katsyv, who was facing a trial in the U.S. liked to his alleged part in the $230 million fraud uncovered by Magnitsky.

She applied in the Southern District of New York for that temporary access to be extended beyond Jan. 6, 2016, when it was due to expire. Just five months later, she would be riding the Trump Tower elevator to meet the top aides of the next president of the United States.

Manafort, Kushner, and Trump Jr were secretly meeting the lawyer of a Russian businessman whose assets had been frozen by the U.S. government while he awaited trial.

Rob Goldstone, a music publicist who is close to Trump Jr., claimed he had set up the meeting on behalf of one of his clients, whom he did not name.

Goldstone’s lively Instagram feed features an image of singer Emin Agalarov, whose father is billionaire Moscow developer Aras Agalarov, on a Florida golf course with Donald Trump.

Goldstone changed his Instagram settings to private on Sunday evening. But the men can be seen together elsewhere. An image from the 2013 Miss Universe pageant shows Emin and Aras Agalarov alongside Trump, who also appeared in a music video with Emin that year. The Washington Postreported that Aras Agalarov had tried to arrange for Putin to attend the pageant and was acting as a liaison between Trump and Putin.

Agalarov was also named in the dossier compiled by ex-British spy Christopher Steele, which alleged the existence of a conspiracy between the Trump campaign and the Russian government during the 2016 presidential election.

Soon after the 2013 pageant in Moscow, Agalarov, who’s been granted exclusive state contracts in the past, was awarded the “Order of Honor of the Russian Federation.” Trump and Agalarov reportedly discussed a deal to build a Trump Tower in Russia.

Goldstone has been a judge at Miss USA and Miss Universe in the past. He attended the meeting with Veselnitskaya at the Trump Tower on Fifth Avenue last summer. “Once she presented what she had to say, it was like, ‘Can you keep an eye on it? Should [Trump] be in power, maybe that’s a conversation that he may have in the future?’” he recalled to The Washington Post.

Veselnitskaya told The New York Times that the meeting lasted about half an hour. “Nothing at all was discussed about the presidential campaign,” she said. “I have never acted on behalf of the Russian government and have never discussed any of these matters with any representative of the Russian government.”