Barclays former chief executive Bob Diamond has called the behaviour of those responsible for rigging the rates at which the bank said it was borrowing money "reprehensible".
Diamond, who resigned over the Libor scandal, said the traders responsible were not a true reflection of the bank's culture.
He was facing a grilling from MPs over the revelations which have sent shockwaves through the global banking system.
The wrongdoing was "not representative of the firm that I love so much", the American banker said. But he also insisted that Barclays was being made a scapegoat because it had cooperated with the authorities to help unearth the misdeeds.
"This week the focus has been on Barclays because they were the first," Diamond, 60, said, describing years of cooperation with regulatory agencies to uncover the practice.
"I think it's a sign of the culture of Barclays that we were willing to be first, we were willing to be fast and we were willing to come out with this."
Of his own decision to step down, a day after saying he wouldn't, he said he had realised that he had become a lightning rod for criticism. "The focus of intensity was my leadership. It was better for me to step down."
Barclays has acknowledged that its traders colluded with others to manipulate the London Interbank Offered Rate, or Libor, the rate that big banks say they borrow from each other which underpins trillions of dollars in global contracts.