Rory Cullinan, right, with Bruce Van Saun, the CEO of Citizens Financial Group, in New York City in September.

Snapchat may have cost Royal Bank of Scotland chairman Rory Cullinan his job.

At the beginning of March, The Sun newspaper reported that Cullinan sent his 18-year-old daughter, Bridget, a series of messages from the Snapchat app, saying he was “bored” at work.

Snapchat puts a time limit on how long recipients can view and download photos, videos, or messages, but Cullinan’s daughter took screengrabs on her phone and put them on the photo-sharing app Instagram.

The images were sent with captions including: “Not a fan of board meetings xx,” “Boring meeting xx,” and “Another friggin meeting.”

Here is one of them:

To be fair to Cullinan, the private messages seem like the kind of normal, run-of-the-mill stuff any father might send his daughter during a break at the office. He obviously didn’t intend them for public consumption.

But weeks later, RBS announced in a regulatory statement that Cullinan would leave the bank on April 30. The exit is a shock because Cullinan on March 4 was promoted to lead the restructuring of RBS’ investment-banking arm.

Cullinan was one of the highest-paid bankers at RBS. He received £2.2 million ($US3.3 million) from bonuses over the past six years and redeemed £1.2 million ($US1.8 million) worth of shares. After his promotion, he also secured another £2 million ($US2.9 million) salary and rewards.

He is now on his way out.

The statement did not give a reason for Cullinan’s departure. RBS CEO Ross McEwan said only that “we would like to express our thanks to Rory for his very significant contribution to the rebuild of RBS over the past six years.”

Cullinan said in a statement: “I am pleased and proud to have played a significant part in restoring RBS to a safe and sound agenda over the past six years.”

The Telegraph first pointed out that Cullinan was leaving the bank only a few weeks after the publication of the Snapchat pictures.

The Guardian newspaper, however, suggested that Cullinan left the bank because he “disagreed with colleagues about how to implement strategy at the loss-making bank now run by McEwan.”