U.S. Senator Elizabeth Warren (D., Mass.) on Friday called for a congressional hearing into allegations that regulators at the Federal Reserve Bank of New York were too close to the banks they supervised.

“Congress must hold oversight hearings on the disturbing issues raised by today’s whistleblower report when it returns in November, because it’s our job to make sure our financial regulators are doing their jobs,” Ms. Warren said.

A report by nonprofit news organization ProPublica and the “This American Life” program of radio station WBEZ Chicago brought to light a secret internal review commissioned by the New York Fed in 2009.