In a letter to the chairman of the UK's Treasury Select Committee, Diamond wrote that he is happy to answer questions to an extra convened committee.
Diamond said the principal message of the investigation carried out by UK and US authorities was that "Barclays (sic) actions did not meet the high standards we set for ourselves."
Moreover, in the letter to UK Conservative politician Andrew Tyrie, Barclays' CEO dubbed the conduct of traders to influence inter-bank interest rates for their own benefit "wholly inappropriate" and that "the control systems in place at the time were not strong enough".
Chairman Tyrie has said that the Treasury Committee will look into Barclays' malpractices relating to how the London Interbank Offered Rate and Euro LIBOR rates are set. Speaking to the Daily Telegraph, Tyrie said that the committee will ask serious questions not only to Diamond but to regulators as well.