When Antonio Reynoso succeeded Eric Adams as the borough president of Brooklyn, he followed Mr. Adams’s lead and began to engage in activities one might not normally associate with his local office: international relations.

When foreign consulates reached out, he took meetings, holding as many as two to three a week. When consulate officials and local leaders asked him to lead ceremonial events celebrating their countries’ heritage, he agreed.

But over time, Mr. Reynoso’s discomfort grew, he said. Modest gifts had come in from foreign consulates: a bottle of wine, a bookmark. But then Turkish officials began to increase their generosity.

They offered junkets to Turkey and wanted Mr. Reynoso to raise their native country’s flag over Brooklyn Borough Hall. Ten gold-plated tea sets arrived as a gift from the Turkish consulate. Mr. Reynoso said he promptly returned them.

“As much as we are grateful for these gifts, I have been advised by my counsel that I must return them to you,” Mr. Reynoso wrote in a letter in March 2022 to Reyhan Özgür, the former Turkish consul general in New York.

Soon after, at the suggestion of the Mayor’s Office of International Affairs, Mr. Reynoso met with F.B.I. officials, who warned him to be wary of officials representing particular foreign countries, including Turkey.