Federal prosecutors are preparing to charge longtime GOP fundraiser Elliott Broidy in connection with efforts to influence the U.S. government on behalf of foreign interests, according to people familiar with the matter, a result of a sprawling, years-long investigation that involved a figure who helped raise millions for Donald Trump’s election and the Republican Party.

Broidy is under scrutiny for his alleged role in a campaign to persuade high-level Trump administration officials to drop an investigation of Malaysian government corruption, as well as for his attempt to push for the extradition of an outspoken Chinese dissident back to his home country, according to the people, who, like others interviewed for this report, spoke on the condition of anonymity to describe an ongoing investigation.

He has been in discussions with the Justice Department and could ultimately reach a plea deal, they said.

The case has intensified in recent weeks, with prosecutors securing a guilty plea Monday from one of Broidy’s business associates, Nickie Mali Lum Davis, who admitted to taking part in what prosecutors have described in charging documents as a “back-channel lobbying campaign” to end the Malaysian corruption investigation and to return Chinese exile Guo Wengui to his home country.

Guo is a vocal online critic of the Chinese government who was once allied with that country’s government elite but is now wanted by authorities in Beijing on charges of fraud, blackmail and bribery. He has denied those charges and said they are politically motivated.

According to a charging document filed in her case, Davis admitted she aided and abetted the efforts of two others involved in the influence campaigns, identified only as Person A and Person B. People familiar with the matter identified them as former Fugees rapper Pras Michel and Broidy, respectively.

During a virtual hearing Monday before a federal judge in Honolulu, where Davis entered her guilty plea, prosecutors told a judge that charges may be filed against additional defendants in the case.

The Justice Department declined to comment. An attorney for Broidy declined to comment.

A previous attorney for Broidy has said he has “never agreed to work for, been retained by nor been compensated by any foreign government for any interaction with the United States government, ever.” Broidy told the New York Times in 2018 in a statement: “This whole narrative is a fabrication driven by hackers who want to undermine me.”

Michel has similarly denied wrongdoing. His attorney declined to comment.

The investigation puts a renewed focus on efforts by people close to the president to shape the fate of Guo, who has succeeded in remaining in the United States.

In the past few years, the Chinese billionaire has been closely aligned with Stephen K. Bannon, Trump’s former campaign chief and top White House strategist. Bannon was on Guo’s yacht off the coast of Westbrook, Conn., when he was arrested last month on charges he fleeced donors who supported a group that claimed to be building a wall on the U.S.-Mexico border.

The investigation of Broidy has its roots in a massive probe of theft from a Malaysian government development fund that has come to be known by the shorthand “1MDB.” In previous civil and criminal cases, federal prosecutors have alleged that stolen money that made its way into the United States was used to buy pricey real estate and even fund the award-winning movie “The Wolf of Wall Street.” Malaysia’s former prime minister Najib Razak was accused of being involved in the corruption. He was convicted in July and sentenced to 12 years in prison.

At the center of the case is a Malaysian businessman named Low Taek Jho, who was indicted in 2018 and accused of funneling tens of millions of dollars into the United States in part to get the Malaysian corruption investigation dropped. Low, who is facing multiple federal indictments, is believed to be in China, outside the reach of U.S. authorities. He has denied the allegations and said they are politically motivated.

According to court documents filed in association with Davis’s guilty plea this week, Broidy allegedly lobbied to have Guo removed from the United States at the request of Low and a Chinese government official.

Davis admitted she met with the Chinese official — who people familiar with the matter identified as Sun Lijun — and the two people identified as Broidy and Michel in a Hong Kong hotel suite in May 2017, and Broidy soon launched a campaign that reached the top of the administration, court filings show.

According to the documents and people familiar with the matter, Broidy allegedly made various entreaties to people in the administration or close to it, including President Trump’s then-chief of staff, Reince Priebus; his former deputy campaign chairman, Rick Gates; and the president himself.

At one point, Broidy also tried to enlist the help of casino magnate and Trump friend Steve Wynn, according to the documents and the people with knowledge of the case. In August 2017, Broidy and Wynn called Trump from Wynn’s yacht and asked about Guo’s status.

Davis also admitted in court that she connected multiple calls between Wynn and Sun.

Reid Weingarten, an attorney for Wynn, declined to comment but said his client has been cooperating with investigators and continues to do so.

Wynn and Broidy worked together as finance chairman and deputy finance chairman of the Republican National Committee after Trump’s election.

Wynn made his own attempt to pass a message about Guo directly to Trump from Chinese President Xi Jinping, according to two people with knowledge of the episode. In a private meeting around June 2017, Wynn told Trump why Xi felt so strongly about the United States returning Guo to China, handing Trump two pictures of Guo, the people said.

At the time, Wynn had significant business interests involving China, operating a major casino in Macao.

Trump was eager to extradite Guo, as the Chinese wished, telling aides in an Oval Office meeting that he supported the plan, according to a former administration official familiar with his views.

Priebus passed along the extradition request to the National Security Council, where it was vetted by a senior White House lawyer, John Eisenberg, who conferred with then-White House Counsel Donald McGahn, the official said.

White House lawyers agreed that extradition, which was opposed by the Justice Department, would not be appropriate, according to the official. McGahn later told aides who asked about the status request, “We killed that,” the official said.

McGahn did not respond to requests for comment. A White House spokesman referred questions about the episode to the National Security Council. An NSC spokesman declined to comment and referred questions to the Justice Department.

During the 2016 campaign, Broidy, a Los Angeles-based investor, helped corral big donors to support Trump’s campaign. After the election, he was appointed to serve as a national deputy finance chairman for the Republican National Committee.

Broidy resigned from that post in April 2018 in the wake of a report that he had paid a former Playboy model $1.6 million in exchange for her silence about a sexual affair. Trump’s personal attorney Michael Cohen — another RNC fundraiser — helped arrange the settlement, Broidy acknowledged at the time.

As part of the Malaysian corruption probe, the U.S. government has previously alleged that Michel and a former Justice Department employee, George Higginbotham, opened U.S. accounts to move Low’s money into the United States and fund the lobbying effort.

Davis acknowledged that she helped route an $8 million retainer to Broidy for the influence campaign and that Low offered to pay a $75 million “success fee” as part of a contract with Broidy’s wife’s law firm if the 1MDB case was resolved within 180 days.

Higginbotham pleaded guilty in November 2018 to illicitly facilitating the transfer of tens of millions of dollars into the United States to finance the lobbying effort.

According to Davis’s criminal information and people familiar with the matter, Broidy met with Trump at the White House in October 2017 and told others that he raised the subject of the 1MDB investigation.

A former attorney for Broidy told the Wall Street Journal in 2018 that at no time did Broidy, his wife, “or anyone acting on their behalf, discuss Mr. Low’s case with President Trump, any member of his staff, or anyone at the U.S. Department of Justice.”

Text messages and emails quoted in Davis’s plea documents show that Broidy messaged Gates, Trump’s former deputy campaign chairman, and Priebus in 2017 about arranging a visit for Malaysia’s prime minister and a possible golf outing with Trump. An attorney for Gates declined to comment.

Priebus responded but was noncommittal, saying the NSC was working on the matter, according to court filings and the people. Priebus declined to comment.

The prime minister did visit, but he did not golf with Trump, according to the court documents. The meeting was meant in part so the Malaysian prime minister could press Trump about ending the 1MDB case, according to the documents.

Josh Dawsey contributed to this report.