Rudolf Elmer, a former chief operating officer with Julius Baer in the Cayman Islands who handed internal bank data on tax evaders to WikiLeaks, international tax authorities and allegedly the media has not broken Switzerland’s bank secrecy law, the country’s Supreme Court confirmed last week.

Mr. Elmer was acquitted in 2016 on charges brought under the Swiss Banking Act, because, according to the Upper Court, the law did not apply to him as an employee of the Caribbean subsidiary of the Swiss bank.

Prosecutors had appealed that decision, arguing that it would erode Swiss bank secrecy “with far-reaching consequences that cannot be accepted,” if Swiss bank employees outside of the country were not subject to the law.

The Swiss Banking Act requires employees of Swiss-regulated banks to keep client information confidential, but in recent years several whistleblowers have leaked account details to foreign authorities amid a crackdown on tax evasion.

The Supreme Court upheld the earlier verdict on appeal.

While breaking bank secrecy is a criminal offense in Switzerland, the court ruled again that Julius Baer’s Cayman subsidiary could not be considered a Swiss bank.

Despite the rhetoric of the prosecutors’ legal arguments, the future impact of the latest verdict on Swiss banking secrecy is limited. Switzerland’s participation in tax information exchange initiatives has already ended bank secrecy for tax purposes.

The country remains the world’s largest wealth management center for overseas clients, even after it responded to pressure from the European Union and the United States to become more transparent and to participate in the exchange of taxpayer data.

Switzerland complies with both the Foreign Account Tax Compliance Act, which forces financial institutions to report U.S. taxpayer information to the Internal Revenue Service, and the Common Reporting Standard, which governs the exchange of taxpayer details between more than 100 countries.

At the end of last month, Switzerland officially started to automatically share client data with tax authorities in dozens of countries, the country’s Federal Tax Administration announced.

The initial exchange began with European Union countries plus nine other jurisdictions: Australia, Canada, Guernsey, Iceland, Isle of Man, Japan, Jersey, Norway and South Korea.

Cyprus and Romania are currently excluded as they do not yet meet the international requirements on confidentiality and data security, the FTA said.

The transmitted information includes the asset owner’s name, address, country of residence and tax identification number as well as the reporting institution, account balance and capital income.

Bank Julius Baer was not part of the proceedings. The bank admitted in 2016 that it helped thousands of Americans hide billions of dollars in assets and agreed to pay $547 million under a deferred prosecution agreement with the U.S. Justice Department.

Mr. Elmer began his career with the private bank in 1987 as an auditor in Switzerland before he moved to the Cayman Islands in 1994. He became the chief operating officer of Julius Baer Bank & Trust Company Ltd. in 1999 and was sacked in 2002 because he was allegedly involved in the theft of client data.

Mr. Elmer has always maintained that he made back-up copies of client data in the event of a hurricane.

He was arrested in Switzerland in 2005 and again in 2011 after he had handed two CDs to WikiLeaks founder Julian Assange at a London press conference.

In 2015, he was convicted of violating Swiss banking secrecy.

A year later, the Zurich upper court acquitted him on appeal on the violation of bank secrecy laws but handed him a suspended sentence for threatening Julius Baer following his dismissal and forging a letter from Julius Baer that implied German Chancellor Angela Merkel had a Swiss bank account.

The appeals court at the time rejected that Mr. Elmer was a whistleblower, suggesting he was motivated by revenge against his former employer.

Mr. Elmer denied the charges.