Former BNM governor Tan Sri Zeti Akhtar Aziz said the three letters, dated Nov 1, 2011; March 1, 2013 and June 1, 2014; had never been disclosed to the central bank and were only discovered during a joint raid by BNM and the Malaysian Anti-Corruption Commission (MACC) at AmBank on July 6, 2015. - Photo by Bernama