Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Senior White House Official Testifies Privately in Trump Impeachment Probe Wayne Lee WASHINGTON - A senior White House budget official arrived on Capitol Hill Saturday to testify behind closed doors before congressional investigators who are conducting an impeachment inquiry against U.S. President Donald Trump. Mark Sandy, a longtime career official with the Office of Management and Budget, is the first agency employee to be deposed in the inquiry after three employees appointed by Trump defied congressional subpoenas to testify. It remains unclear if a subpoena had been issued to Sandy. Sandy could provide valuable information about the U.S. delay of nearly $400 million in aid to Ukraine last summer, allegedly in exchange for the newly-elected Ukrainian president to launch investigations into 2020 Democratic presidential hopeful Joe Biden and his son at Trump's request. Investigators are also exploring debunked claims promoted by Trump and allies that Ukraine, and not Russia, interfered in the 2016 U.S. presidential election. Sandy was among the career employees who questioned the holdup, according to people with knowledge of the matter. His signature is on at least one document that prevented the provision of the aid to Ukraine, according to copies of documents investigators discussed during an earlier deposition. A transcript of the discussion has been publicly disclosed. Sandy appears before the House foreign affairs, intelligence, and oversight and reform committees. .