The FBI has opened an investigation into potential campaign finance violations committed by Cindy Li Yang, a Republican donor from Florida who is accused of selling Chinese access to President Donald Trump and his administration.

Investigators obtained a federal subpoena on Tuesday seeking records from Bingbing Peranio, an employee of Yangs familys massage parlor business who contributed the maximum $5,400 last year to Trumps 2020 reelection effort, according to The Miami Herald . Yang allegedly helped her write the contribution check, and Peranio did not reject the help, The New York Times reported in March.

The FBIs subpoena requests any records related to Peranios March 5, 2018, contribution, as well as any other donations from 2014 until now, a source familiar with the probe told the Herald. Peranio later confirmed to the Herald that she received a subpoena and was interviewed by FBI agents on Thursday.

Investigators in Florida are trying to determine if Yang paid Peranio back for that contribution to the Trump campaign. It is against the law to reimburse someone for a political contribution without disclosing the original source or to make a contribution in someone elses name.

Turk Law Group, the law firm representing Yang, told HuffPost that the FBI has not contacted them.

[O]ur firm has not been contacted about our client, Karyn Turk, the firms business development director, said. We had communication with our client this morning and she also had not been contacted as of that conversation.

Yang, a naturalized U.S. citizen from China, is accused of selling Chinese investors access to Trump through GY US Investments LLC, a company belonging to her and her husband, Zubin Gong. The business offers fee-paying clients the opportunity to interact with the president, the [U.S.] Minister of Commerce and other political figures and makes arrangements for White House and Capitol dinners, according to a translation of the firms now defunct website, according to Mother Jones.

Chinese executives could also get access at the presidents Mar-a-Lago club in West Palm Beach, Florida. Yang became a promoter of events at Mar-a-Lago in 2018, and she and her guests have attended multiple Trump campaign events.

Yangs activity raised questions of whether she was using foreign money to buy tickets for political campaign events, which is illegal in the U.S. unless contributors have a green card. Yang stopped her fundraising for the Trump campaign and joined an Asian American GOP group after she had opposed a Republican National Committee rule meant to keep out foreign money, the Asian American groups executive director told the Herald.

Several top Democrats on the Senate Intelligence and Judiciary committees had called for the FBI to investigate Yang over allegations of human trafficking, foreign lobbying and campaign finance violations. Yang founded a chain of Florida massage parlors that were recently in the spotlight for allegedly providing sexual services for high-profile clients and for being at the center of an alleged trafficking ring.

If true, these allegations raise serious counterintelligence concerns, Democrats wrote in a March 18 letter to directors of national intelligence, the FBI and the Secret Service. China has frequently used non-traditional intelligence collectors and businesspersons to compromise targets.

Yang rejected the claims during a March 20 interview with NBC , saying she has no allegiance to China and that she was being attacked because shes a Chinese Republican.

The investigation comes as Trumps talks of tariffs with China continue to escalate. The president said Thursday that the U.S would raise tariffs on $200 billion worth of Chinese goods at midnight Friday and was moving toward taxing nearly all of Chinas imports after he accused Beijing of backing out of a trade deal.

This story has been updated with comment from Turk Law Group.