The US Department of Justice will not reopen a criminal investigation into former Federal Reserve Chair Jerome Powell regarding cost overruns on the central bank's building renovation project.

US Attorney General Todd Blanche did not rule out continuing to review the oversight of the project or taking action if evidence of wrongdoing emerges.

"We are not going to reopen a criminal investigation into him," Blanche said in an interview on Friday.

Blanche made the remarks while commenting on a report released this week by the Fed's inspector general, which found no evidence of criminal wrongdoing by Powell in the $2.4 billion project.

Blanche said he was satisfied with the report but believed Powell did not provide proper oversight of the project.

The Fed said it will hire an independent auditor to review the costs related to the building.

Blanche added that if the review uncovers any evidence of criminal wrongdoing, the Justice Department may open an investigation.