WASHINGTON—Maria Butina, the 29-year-old Russian accused of being an unregistered foreign agent, used her connections to a Russian central bank executive to attend meetings with U.S. government officials, including one with the vice chairman of the Federal Reserve in 2015.

Former Federal Reserve Vice Chairman Stanley Fischer confirmed her presence at a meeting in April of that year. Ms. Butina was there as an interpreter for her patron, Alexander Torshin, who was then deputy governor of Russia’s central bank. Mr. Torshin has...