(Reuters) – Federal Reserve Chair Jerome Powell has ordered a sweeping review of the ethics rules governing financial holdings and dealings by senior officials at the U.S. central bank, a Fed spokesperson said on Thursday.

According to a spokesperson, Powell requested the review in late September. This follows recent revelations that Powell was one of 12 Fed region bank presidents who were actively investors. The Wall Street Journal first reported the revelations. Senator Elizabeth Warren, Massachusetts, was among those who demanded more strict restrictions.

According to the spokesperson, “Because it is vital for the Federal Reserve’s effective mission to carry out its important mission, Chairman Powell last week ordered Board staff to review the ethics rules surrounding permissible financial activities and holdings by senior Fed officials.”

According to the spokesperson, Fed officials follow the same rules as other government agencies regarding personal financial decisions. The Fed also has additional rules, which are more strict than the ones for Congress or other agencies and are tailored to its work.

This review will help identify ways to tighten these standards and rules. A spokesperson stated that the Board would make any necessary changes and will add them to the Reserve Bank Code of Conduct.