The chairman of the House subcommittee that oversees the Federal Reserve demanded Tuesday that the Fed fully disclose details of billions -- perhaps trillions -- in secret emergency loans it made to almost every major bank in the U.S. and overseas during the financial crisis or face a congressional subpoena for the information.

In an interview with Fox Business, Rep. Ron Paul (R-Texas), chairman of the House Financial Services subcommittee on domestic monetary policy, said he wants to know “how much, when, where and why” from Fed officials when they testify about the loans at a subcommittee hearing Wednesday.

“We’re going to get to the bottom of what the Fed did during the big bailout a couple of years ago,” Paul said. “We have some precise questions. I imagine we won’t get all of them answered tomorrow because they’ll do a little bit of stonewalling, I’m sure.”

“If they don’t answer, they’ll hear from us,” he said. “We can use the subpoena power and say, ‘Look, you have to bring us the records.’ ”