The Russian lawyer who peddled dirt on Hillary Clinton to Donald Trump Jr. has ties to former Russian military and intelligence officials, a key congressional committee will hear in testimony next week.

William Browder, an American financier who has investigated Russian corruption for more than a decade, will brief the Senate Judiciary Committee at a hearing next week on 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. Those ties were spelled out in documents that Browder shared with the committee and provided to The Daily Beast this week.

“Veselnitskaya may have had her own agenda in requesting a meeting with Trump,” according Rolf Mowatt-Larssen, a former CIA officer who led the agency’s European directorate of operations. “But Russian intelligence practice is to co-opt such a person by arming them with secret intelligence information and tasking them to pass it to Trump’s people and get their reaction.”

“The key point is that essentially no Russian citizen or lawyer has compromising material on Hillary Clinton which has not been supplied to them from Russian intelligence,” Mowatt-Larssen wrote on Tuesday. “The simple assertion that she had such information is tantamount to declaring that Veselnitskaya was acting as agent of Russian government in this particular role.”

Five days after Veselnitskaya met with Trump Jr. and other senior members of the Trump campaign, the Democratic National Committee revealed that its email servers had been hacked. The culprits, U.S. intelligence would later announce publicly, were Russian hackers working on behalf of the country's military intelligence agency, the GRU, and its Federal Security Service, or FSB.

The documents provided by Browder delve into the backgrounds of attorneys, lobbyists, and business executives behind what Browder says is a concerted push by the Russian government to roll back U.S. sanctions imposed in 2012. That network is also at the center of new evidence that Donald Trump Jr., the president’s eldest son, solicited damaging information on Democratic presidential nominee Hillary Clinton from people whom he was told were representing, and passing on information from, the Russian government.

Recent developments on Trump Jr.’s communications with those individuals, and additional details that Browder has shared with the committee and will recap next week, threaten to spoil an opportunity for Republicans to sow doubt about allegations of Trump-Russia collusion. The involvement of figures at the center of Browder’s allegations in the emerging Trump Jr. scandal threaten to turn the hearing into an examination of the Trump campaign’s apparent willingness to enlist Russian government agents on its behalf.

The hearing was planned months ago, Browder told The Daily Beast on Monday, and will examine a group called the Human Rights Accountability Global Initiative (HRAGI) Foundation, a group that has lobbied Congress to roll back the Magnitsky Act. That law was named after Russian lawyer Sergei Magnitsky, who was kidnapped, tortured, and executed in 2009 after working to expose high-level Russian government corruption.

Browder was a friend and client of Magnitsky’s, and has worked for years to pass, and then preserve, the sanctions imposed by the law on individuals and entities suspected of complicity in Magnitsky’s murder. Browder filed a complaint with the Department of Justice this year alleging that HRAGI, its attorney Natalia Veselnitskaya, and a number of other Russian individuals and companies were lobbying for Magnitsky’s repeal on the Russian government’s behalf.

Veselnitskaya told NBC News on Tuesday that she sought a meeting with Trump Jr. solely to discuss issues surrounding Magnitsky sanctions and has “never worked for [the Russian] government.” But that’s not what Browder is alleging. Her client list and circle of anti-Magnitsky advocates, he says, include former Russian government officials—including a former counterintelligence operative and a close colleague of a former state security official—and government-owned companies considered close to President Vladimir Putin’s regime and susceptible to the influence of Russian intelligence agencies.

The overlap between nodes of Veselnitskaya’s anti-Magnitsky activities and apparent Russian government-linked entities is “all classic organization structure for intelligence operations,” a former Central Intelligence Agency field officer told The Daily Beast when presented with the evidence that Browder had gathered.

“Good intelligence operations always will appear legitimate. They will be legitimate. But not only legitimate,” the former US intelligence veteran explained in an email. “I was a diplomat. I did real work. But I was also an intelligence officer acting operationally every day. It is the same for the structures [detailed in Browder’s research]: They are real. They intentionally mask FSB activity and involvement. They cover it and make it possible. The intelligence activity is the POINT of the structures.”

According to a Wednesday report from McClatchy, Veselnitskaya occasionally made her FSB links explicit. When a human rights group in Russia began investigating alleged corruption involving one of her clients, Veselnitskaya reportedly told the group’s leader that the FSB would come after the organization if it persisted.

Vesilnitskaya represents HRAGI, which has reported lobbying Congress on issues pertaining to a ban on the adoption of Russian children by American families. In a very broad sense that is accurate—the ban was imposed by President Vladimir Putin as retaliation for the Magnitsky Act—but Browder says the group’s primary goals are to rescind sanctions and discredit those, like Browder, pressing for their preservation.

Among HRAGI’s lobbyists is Rinat Akhmetshin, who has described himself as a former Russian counterintelligence officer, but said he is no longer in the government’s employ. HRAGI removed Akhmetshin from its roster of lobbyists on May 8, five days before the Justice Department settled a long-running corruption case against a Russian company called Prevezon Holdings. Prevezon’s owner is an HRAGI lobbying client. Veselnitskaya is his lawyer.

HRAGI’s other clients include Vladimir Lelyukh, a top executive at Sberbank Capital, a subsidiary of the state-owned Russian bank involved in the real estate, energy, transportation, and automotive sectors. Sberbank Capital’s CEO, Ashot Khachaturyants, is a former senior official in Russia’s Federal Security Service (FSB) and its Ministry of Economic Development and Trade.

State-owned Russian financial institutions are common conduits for surreptitious intelligence work in the country. Jared Kushner, the president’s son-in-law and senior adviser, has faced scrutiny over a January meeting a top executive at another bank with ties to Russian intelligence, Moscow-based Vnesheconombank.

The initial connection between Veselnitskaya and Trump Jr. came by way of Emin Agalarov, a Russian pop star and real estate investor, and his father, Azerbaijani-Russian businessman and Putin ally Aras Agalarov. They had met Trump Jr. when the Miss Universe pageant was hosted in Moscow in 2013. During that visit, the Agalarovs met for dinner with the elder Trump and Herman Gref, Sberbank’s chief executive and one of the pageant's official sponsors.

Gref, Khachaturyants, Sberbank, and Sberbank Capital were all named as defendants in a lawsuit filed in a federal court in new York last year alleging they were complicit in efforts by close Putin associates to fraudulently take control of a Russian granite company.

In March, Sberbank brought on a new attorney to fight those charges—a lawyer who has become a household name this year.

The lawyer was Marc Kasowitz. He now represents the President of the United States.

A spokesman for Kasowitz did not respond to questions about how he came to represent Sberbank, but new information presented at next week’s hearing could lead to questions from committee Democrats on those and other unexplored Russia connections.

That could dramatically alter the direction of the Browder hearing. Its initial focus appeared to tee up committee Republicans to cast doubt on allegations of Trump-Russia. Now talk of Trump Jr.’s Kremlin contacts will likely dominate the event.

Of particular interest to Grassley is the involvement of Washington political research firm Fusion GPS. Browder singled out the firm for its alleged involvement in the anti-Magnitsky effort. It was also involved in the creation of a research document last year that claimed the Russian government had collected blackmail material on Trump, and that his team had colluded with Russian government agents to hobble the Clinton campaign.

Most of the Steele dossier—named for its author, a former British intelligence agent—remains unverified. The dossier, and Fusion GPS’s role in it, has been invoked by defenders of the president—including his legal team—to cast doubt on collusion allegations, and prior statements from Grassley indicated he would likely take that tack during the hearing.

Fusion GPS says it had nothing to do Trump Jr.’s meeting, and that its role in the anti-Magnitsky push extended only to a legal sub-contract involving the case brought against Prevezon in 2013. “Fusion GPS learned about this meeting from news reports and had no prior knowledge of it,” the firm said in statement. “Any claim that Fusion GPS arranged or facilitated this meeting in any way is false.”

The firm’s apparently peripheral involvement in the larger scheme to, in Browder’s telling, roll back Magnitsky sanctions nevertheless spurred Grassley to dig further into Fusion GPS’s involvement. But now, with new revelations regarding Trump Jr.’s attempts to solicit opposition research from foreign agents, the thrust of Judiciary’s hearing appears poised to shift considerably.

A spokesperson for the committee did not respond to multiple requests for comment on the hearing.

Browder’s Justice Department complaint, and Fusion GPS’s involvement in it, have been invoked to suggest that the Russian government may not have been so clearly in Trump’s camp last year. For Judiciary Committee Republicans, Trump Jr.’s emails have made that position considerably more difficult.

At the very least, those emails will provide the committee’s Trump critics with plenty of ammunition to turn the Browder hearing’s focus from the Steele dossier directly back onto the administration and its Russian contacts.

Updated 10 a.m. 7/12 with new information and comment.