New Delhi, Jan. 12 -- The dollar fell the most in three weeks in overnight trading, while Treasury bond yields retreated and gold soared to a fresh record high as global markets reacted to a U.S. Justice Department probe into Federal Reserve Chairman Jerome Powell and a new series of interventions from President Donald Trump.

Powell said the central bank received notice of grand jury subpoenas from the Justice Department related to his testimony to congressional lawmakers regarding the unfinished refurbishment of the Fed's headquarters in Washington.

Powell forcefully suggested a political motive behind the probe, which comes just four months ahead of the end of his eight-year term as Fed chair in May and extends a series of attacks on ...