London (CNN) -- Former Barclays bank chief executive Bob Diamond will voluntarily give up bonuses worth $31 million after he resigned in the wake of a rate-rigging scandal, the bank said Tuesday. Diamond will still receive 12 months salary after his resignation last week, the bank said Tuesday. That's £1.35 million (about $2 million), according to the bank's annual report. It is twice as much as he is entitled to under his contract, which has a six-month notice period, bank chairman Marcus Agius said. Barclays will also pay Diamond's legal bills if he faces criminal investigation, a source close to the bank told CNN Tuesday. The source asked not to be identified because of the sensitivity of the information.
@highlight
NEW: Barclays will pay the legal bills of former chief Bob Diamond if necessary, a source says
@highlight
Chairman Marcus Agius is giving evidence on a rate-rigging scandal
@highlight
Agius says Barclays deeply regretted the circumstances that led to Diamond resigning
@highlight
Diamond will still receive a year's salary, the bank says
@placeholder' reputation has been hammered by a scandal over the rates at which banks lend each other money.