RBS investment banking head Rory Cullinan is to leave his role on April 30, only a month after he was appointed to the role.

Cullinan had been charged with managing the shake-up of the lender’s investment banking business.

The move comes after messages he sent to his daughter were revealed online, which showed that he was bored at work.

Prior to this role, Cullinan served as head of RBS’s internal bad bank, which comprises unwanted assets that the bank intends to dissolve or sell.

Chris Marks, currently serving as chief executive of the corporate and institutional banking unit, and Mark Bailie, chief executive of the capital resolution business, will become co-chief executives of the division.

RBS chief executive Ross McEwan said, "We would like to express our thanks to Rory for his very significant contribution to the rebuild of RBS over the past 6 years. He has built and led APS, Non-Core, RCR and recently completed the very successful follow-on sale of Citizens post its IPO last year."