Former bank trader Tom Hayes accused top Citigroup executives of being involved in efforts to manipulate global benchmark rates and then engineering a cover-up, a London court heard on Monday.

Brian McCappin, chief executive of Citi's global markets business in Japan, "would talk to the cash desk in Tokyo and ask them to move Tibors [Tokyo interbank offered rate],"according to an email sent by Hayes to a contact at Barclays on September 7, 2010, the day after Hayes was dismissed from the US bank.