The Department of Justice is expected to drop its criminal investigation into Federal Reserve Chair Jerome Powell as soon as Friday, ending a standoff that threatened to delay the confirmation of Powell's successor at the central bank, multiple sources familiar with the matter told ABC News. 

Senior DOJ officials have contacted senators in recent days, including Republican Sen. Thom Tillis. who sits on the Senate Banking Committee, informing them of the plan to drop the probe and refer the matter regarding alleged cost overruns at the Fed's Washington headquarters to the bank's internal watchdog, the sources said. 

The Fed's independent inspector general conducted an audit of the building renovation costs in 2021 and Powell had already asked the watchdog to take a fresh look at the $2.5 billion project last year.

Powell's term ends next month, but he said in March that he would stay in the position until President Donald Trump's pick to lead the Fed, Kevin Warsh, is confirmed. 

A spokesperson for the Federal Reserve declined to comment. Reached by ABC News, a spokesperson for Tillis declined to comment.

A Justice Department spokesperson did not immediately respond to a request for comment from ABC News.

District of Columbia U.S. Attorney Jeanine Pirro has been insistent that her investigation of alleged cost overruns at the Fed would continue despite a ruling last month from D.C. District Judge James Boasberg that tossed out subpoenas she had sent to Powell.