Thiel began providing information as a “confidential human source,” or CHS, to Johnathan Buma, a Los Angeles-based FBI agent who specializes in investigating political corruption and foreign-influence campaigns, a report says.

As a CHS, Thiel was assigned a code name and an internal serial number to track his reporting. The information he passed on about foreign contacts and Silicon Valley intrigue was reviewed and “validated,” or cross-checked against other sources, by his case agents and their colleagues.

Thiel did not respond to multiple requests for comment.

Thiel is a citizen of Germany, the United States, and New Zealand; as of last year, he was reportedly in the process of acquiring yet another passport, from Malta. In 2016, he donated $1.25 million to Trump’s campaign and endorsed him from the stage at the Republican National Convention. After Trump won, Thiel served on his transition team.