The chairman of global banking giant Credit Suisse, Antonio Horta-Osorio, has resigned with immediate effect after breaking Covid quarantine rules.
Mr Horta-Osorio, who was with the bank for just nine months, left following an internal investigation.
The former boss of Lloyds Banking Group joined Credit Suisse after a series of scandals at the Swiss bank.
But it has emerged he breached Covid rules last year, including by attending the Wimbledon tennis finals.
"I regret that a number of my personal actions have led to difficulties for the bank and compromised my ability to represent the bank internally and externally," Mr Horta-Osorio said in a statement issued by the bank.
"I therefore believe that my resignation is in the interest of the bank and its stakeholders at this crucial time," he added.
Mr Horta-Osorio has been replaced by board member Axel Lehmann.
Last month, a preliminary investigation by Credit Suisse had found that Mr Horta-Osorio had breached Covid-19 rules.
He attended the Wimbledon tennis finals in July at a time when the UK's Covid-19 restrictions required him to be in quarantine.
Mr Horta-Osorio also breached Swiss Covid restrictions when, according to Reuters, he flew into the country on 28 November but left on 1 December. Swiss rules meant he should have quarantined for 10 days upon his arrival.
Mr Horta-Osorio joined Credit Suisse in April last year following a series of scandals at the bank,
In February 2020, then-Credit Suisse chief executive Tidjane Thiam resigned after it was revealed the bank had spied on senior employees. Mr Thiam denied knowledge of the spying operations.
Credit Suisse has also been hit with huge losses in connection with the failed financial firm Greensill - which backed Liberty Steel - and Archegos, the US hedge fund which collapsed last year.
Last year, in a report into its relationship with Archegos, Mr Horta-Osorio said: "We are committed to developing a culture of personal responsibility and accountability."
There are two narratives emerging from Antonio Horta-Osorio's short-lived tenure at the top of one of Swiss banking giants.
One is that he broke the rules, was investigated and, having been found in breach, was asked to step down.
But allies of the former boss of Lloyds Banking Group insist that the board of Credit Suisse could have censured him rather than forced him out and suggest that the Swiss bank had not appreciated his efforts to reform an executive team and a culture that has been hit a series of scandals in recent years.
Credit Suisse clients lost billions after the bank funnelled them into financial products designed by the collapsed Greensill Capital while the bank itself took a multi-billion hit from the collapse of hedge fund Archegos.
The bank also found itself at the centre of an unusual spying scandal which saw the departure of chief executive Tidjane Thiam.
Ironically, the man Credit Suisse brought in to bring an end to a string of negative headlines is the subject of them this morning.
Justin Tang, head of Asian research at investment firm United First Partners, said Credit Suisse "has been in the 'damaged goods' section for a while now".
"While Horta-Osorio was responsible for the new strategy, his short tenure means that the revamp is likely to only be in the nascent stage. The irony of it is that Horta was hired to fix the reputational damage to Credit Suisse and revamp its risk taking culture in the bank."
In his statement, Mr Horta-Osorio said: "I am proud of what we have achieved together in my short time at the bank."
But George Godber, fund manager at Polar Capital, told the BBC: "Only [nine] months in is not really time to achieve much.
"He was brought in to turn around the business - it is a bank that has been hit by scandal - and so it means that his reign has been cut short.
"Not everybody is above the law for Covid restrictions."
Mr Horta-Osorio was chief executive at Lloyds Banking Group for 10 years, the start of which was marked by a surprise two month leave of absence to deal with severe sleep deprivation.
Later on, amid media reports of an extra-marital affair, Mr Horta-Osorio emailed Lloyds staff, saying: "I deeply regret being the cause of so much adverse publicity and the damage that has been done to the group's reputation.
"I have been a strong advocate of expecting the highest professional standards from everyone at the bank, and that includes me."
Speaking to the BBC, a spokesperson for Credit Suisse said that the bank would give no further details on Mr Horta-Osorio's resignation other than those in its statement.
They also said that there were no plans to release the findings of the investigation.