The chief executive of the banking giant Barclays has resigned over a major interest-rate fixing scandal that has already ousted the company’s chairman. Bob Diamond stepped down just days after Barclays was fined $453 million by U.S. and British authorities for manipulating key interest rates. A British probe found Barclays conspired to manipulate the London Interbank Offered Rate, or Libor, which provides the basis for rates on trillions of dollars in transactions across the globe. The manipulation meant millions of borrowers paid the wrong amount on their loans. Appearing before a British parliamentary committee the day after his resignation, Diamond called his company’s action “reprehensible” but said top executives had moved swiftly to take action.

Bob Diamond: “When I read the emails from those traders, I got physically ill. It’s reprehensible behavior, and if you’re asking me, should those actions be dealt with, absolutely. But I think it’s a sign of the culture of Barclays that we were willing to be first, we were willing to be fast, we were willing to come out with this.”

Diamond is the second top Barclays executive to depart after chairman Marcus Agius resigned last week. Also speaking at the British parliamentary hearing, Labour Member of Parliament George Mudie said Barclays executives had shown negligent behavior.

George Mudie: “That’s not the point, that tells the world with Barclays. That tells the world with Barclays that two chief executives have been running the firm, and it’s been doing fundamentally wrong things. And your senior management have known about it, and they’ve either been too frightened or too disinterested to actually tell the chief executive. And that is a very worrying thing to come out the inquiry.”