SINGAPORE: Credit Suisse Chairman Antonio Horta-Osorio has resigned after flouting COVID-19 quarantine rules, the bank said on Monday, raising questions over the embattled lender's new strategy as it tries to recover from a string of scandals.

The abrupt move comes less than a year after Horta-Osorio was brought in to clean up Switzerland's No.2 bank's corporate culture marred by its involvement with collapsed investment firm Archegos and insolvent supply chain finance firm Greensill Capital.

However, the Portuguese banker's personal conduct has since come under scrutiny, with reports he breached COVID-19 quarantine rules twice in 2021.

"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," Horta-Osorio said in a statement issued by Switzerland's No. 2 bank.

"I therefore believe that my resignation is in the interest of the bank and its stakeholders at this crucial time," he said.

The bank said Horta-Osorio resigned following an investigation commissioned by the board.

In December, Reuters reported that a preliminary internal bank investigation had found that Horta-Osorio attended the Wimbledon tennis finals in London in July without following Britain's quarantine rules. 

Horta-Osorio also broke COVID-19 rules on a visit to Switzerland in November by leaving the country during a 10-day quarantine period, the bank said in December. 

In late December, David Herro, deputy chairman at Harris, the third biggest investor in Credit Suisse, said Horta-Osorio retained his absolute support. 

Credit Suisse, which announced a new strategy in November aimed at curbing a freewheeling culture that has cost it billions, said board member Axel Lehmann had taken over as chairman with immediate effect. 

The bank said Lehmann, the board and the executive board would continue to implement Credit Suisse's strategy.

Lehmann spent over a decade at rival UBS, where his roles included helming the Swiss personal and corporate banking unit of the bank after a nearly two decade stint at Zurich Insurance Group.

Horta-Osorio's sudden exit demoralised staff, with some questioning what was next for the bank.

"What a waste and again we make the headlines for the wrong reason," a senior Credit Suisse private banker said on condition of anonymity as he was not allowed to speak to media.

"In between we froze for one year waiting for the new strategy from the new man!" he said.

(Reporting by Anshuman Daga in Singapore; Additional reporting by Sumeet Chatterjee in Hong Kong and Shivani Tanna and Maria Ponnezhath in Bengaluru; Editing by Himani Sarkar) ((ShivaniJayesh.Tanna@thomsonreuters.com;))