Top executives from Goldman Sachs, J.P. Morgan Chase, General Electric and other firms sat on the boards of regional Federal Reserve banks while their firms benefited from the central bank’s policies during the financial crisis, creating an appearance of a conflict of interest, a federal watchdog said Wednesday.

At least 18 board members of the Fed’s regional banks were affiliated with companies that tapped emergency Fed programs during the financial crisis, according to the Government Accountability Office. But though there was an appearance of a conflict, the watchdog found that none of these firms received special treatment.

The GAO recommended that the Fed better explain the role of these executives in their operations and be more transparent about the role of directors when there is an appearance of a conflict.

“Failing to make the process and decisions more transparent can decrease confidence in the Federal Reserve,” the watchdog said.

In one example, Stephen Friedman was serving as chairman of the board of the Federal Reserve Bank of New York and was a board member at Goldman Sachs when the firm was becoming a bank holding company to gain access to emergency Fed loans. In another case, General Electric chief executive Jeffrey Immelt served on the board of the New York Fed while the central bank gave GE access to a special short-term financing program.

The GAO also recommended the Fed to do more to diversify its boards racially and include more people from labor and community backgrounds.

Congress asked the GAO to conduct the review after the Fed unveiled a range of programs to help banks and other firms weather the financial crisis that began in 2007.

The report was published while the Fed is facing criticism from both parties.

Rep. Barney Frank (Mass.), the top Democrat on the House Financial Services Committee, is trying to curtail the role of the regional banks, which have urged the Fed to take less action to drive economic growth, because of the risk of creating inflation. Frank wants the president to appoint, and Congress to confirm, the leaders of the regional banks, rather than the boards of directors.

Others liberals, such as Sen. Bernard Sanders (I-Vt.), have raised questions about whether the Fed is too close to Wall Street. Sanders said Wednesday that the GAO’s finding that so many executives sit on the boards of regional Fed banks represents “exactly the kind of outrageous behavior by the big banks and Wall Street that is infuriating so many Americans.”

Meanwhile, Republicans say the Fed has put far too much taxpayer money on the line in trying to stimulate the economy and bailing out the private sector. The Fed has been a punching bag in the GOP presidential contest, with Rep. Ron Paul (Tex.) calling for an end to the Fed and Texas Gov. Rick Perry saying that if Fed Chairman Ben S. Bernanke visited his home state, “we would treat him pretty ugly.”

In a letter to the watchdog, Bernanke said the Fed agrees with all of its recommendations and will work to implement them. Goldman and J.P. Morgan declined to comment, while a GE spokesman noted that the report found no conflicts and that the company paid nearly $100 million in fees to take part in the emergency programs.