The U.S. Attorney’s Office for the Eastern District of New York on Tuesday announced that the chairman of former President Donald Trump’s 2017 inaugural committee has been arrested in California.

Prosecutors accused Thomas Barrack and two other men of conspiring to advance the interests of the United Arab Emirates in the United States, specifically by influencing Trump’s foreign policy positions. Barrack served as an informal adviser to the Trump administration on Middle East policy issues, according to the U.S. Attorney’s Office.