Judge says 'no evidence' to justify Federal Reserve probe

A US judge has blocked a Department of Justice investigation of the Federal Reserve in a closely watched case that has raised concerns about political pressure on the central bank and complicated White House efforts to install a new person to lead it.

In his Friday ruling, Judge James Boasberg said federal prosecutor Jeanine Pirro had presented "no evidence" to justify her demands for information from the Federal Reserve.

It is a victory for the Fed, which did not respond to a request for comment.

Pirro said she would appeal the decision, which she said had "neutered" her ability to investigate crime.

"This process has been arbitrarily undermined by an activist judge," Pirro said at a fiery press conference responding to the decision, which quashed subpoenas - orders to compel someone to give testimony - from her office seeking information from the bank about cost overruns at renovations of its offices.

She dismissed questions about whether her pursuit of the issue would complicate White House efforts to replace Federal Reserve chairman Jerome Powell, calling the issue "white noise".

Key Republican senators in Congress have said they will block Trump's nominee to replace Powell, Kevin Warsh, until the investigation is resolved.