Three years ago, the wife of an American scholar accepted a gift of liquor and some baby clothes—and now her husband has been hit with federal charges for allegedly lying about it.

The issue is that David An is a think-tank researcher with a security clearance. And the presents came from an official with Taiwan’s spy agency.

That’s according to a criminal complaint filed earlier this month in federal court in Washington that contains hints of international intrigue and details of a restaurant rendezvous and eavesdropping.

An, a former State Department official and defense contractor who is now a senior research fellow at the Global Taiwan Institute, allegedly lied to the FBI about the gifts and, separately, committed mortgage fraud on a loan application.

An did not respond to requests for comment from The Daily Beast about the charges. Abraham Simmons, a spokesman for the U.S. Attorney’s office prosecuting the case said only, “The documents speak for themselves on this pending litigation.”

It’s unclear why or when the FBI first started investigating An, but an affidavit filed by an agent assigned to the FBI’s counterintelligence branch revealed that in March 2016, federal agents had a warrant to eavesdrop on An’s communications with a Taiwanese official—referred to as TAW3—who allegedly worked for Taiwan’s National Security Bureau.

In the months before, FBI agents allegedly observed An at a Stanford University event alongside an unnamed Taiwanese official posted at the San Francisco office of the Taipei Economic and Cultural Office (TECO), which Taiwan uses as a de facto U.S. mission in the absence of formal U.S. diplomatic recognition. That Taiwanese official, referred to as TAW1 in the criminal complaint, was also an employee of Taiwan’s intelligence agency, the feds say.

At the time of the meeting, An held an interim secret security clearance because of his work as a senior project manager for an unnamed defense contractor, according to the complaint. A LinkedIn profile for him says he worked as a senior project manager at Lockheed Martin from November 2015 to July 2016.

“All work was unclassified since my program is a foreign military sales program so the company tried to keep as much of the work unclassified as possible for export purposes,” An wrote in the profile. An online biography at the Global Taiwan Institute stated that An’s work at Lockheed Martin focused the THAAD ballistic missile defense system.

At one point, An also held a top-secret security clearance through his earlier work for the State Department as an intern and then an action officer in the Office of Regional Security and Arms Transfers in the East Asia-Pacific bureau.

FBI agents appear to have surveilled An and his meetings with TAW1 and another Taiwanese diplomat at least as early as a February 2016 golf game and continuing through meetings at San Francisco-area restaurants on “several occasions” into the summer of 2016.

During a June 2016 restaurant meeting, a Mandarin Chinese-speaking FBI surveillance specialist eavesdropped on a conversation between An, TAW3, and another Taiwanese official. The specialist allegedly overheard the officials encourage An to consult with them more and say they were in need of unspecified assistance from him. The specialist reported An mentioned the words “unclassified” and “drone,” and handed over “a bundle of white sheets of paper” to the officials.

At a meeting in July 2016, FBI agents claim, An’s wife accepted gifts, including a liquor bottle and children’s clothes, from TAW3 and another unnamed Taiwanese official.

Two years later, An agreed to an interview with FBI agents about “his contacts with representatives of the government of Taiwan” and was asked if he held close and continuing contacts with the foreign officials—which security clearance holders are required to report—and if he had ever accepted gifts from them. FBI agents said An failed to report his relationship with the officials and “falsely stated that he had never received gifts from them” despite being “asked this several times during the interview.”

In addition, prosecutors alleged, An committed mortgage fraud, claiming on a loan application $3,490 in monthly income from a lease that didn’t actually exist. In a conversation recorded by the FBI, An allegedly asked a friend to sign a phony lease as he applied for a mortgage because money he was counting on from Airbnb rentals had not come through, the complaint said.

An was arrested Aug. 14 and released on his own recognizance. His arrest comes as the Trump administration has approved the sale of $8 billion worth of F-16 fighter jets to Taiwan. China, which considers Taiwan a renegade province, often objects to U.S. arms sales to Taipei and warned that “the US will have to bear all the consequences” for the sale.