Swiss wealth managers are urging the government to halt the launch of a vast new register of company owners after hackers stole similar data on thousands of people from neighbouring Liechtenstein. The Swiss Association of Wealth Managers has asked Bern to pause the October 1 rollout of its new “transparency register”, which will be accessible by designated authorities and financial institutions subject to anti-money laundering rules but not directly by the public. The association warned the government that concentrating information on the ultimate owners of more than 500,000 companies and other legal entities in one place would create an attractive target for cyber criminals.

The Swiss Bankers Association has separately raised concerns over cyber security and data protection relating to the register, which has been under development for three years in a country known as a haven for often secretive wealth. The financiers’ intervention follows a major breach of Liechtenstein’s equivalent register in late July, in which unknown hackers stole beneficial ownership data relating to about 31,000 companies, foundations and trusts. Authorities have yet to identify the attackers or establish their motive.

Switzerland is creating the register as part of efforts to strengthen its defences against money laundering and meet international standards ahead of a review by the Paris-based Financial Action Task Force next year. From October, companies and other legal entities will be required to report the individuals who ultimately control them to the central federal database. As well as names, the register is due to include data on dates of birth, nationalities, postcodes and places of residence.

The stakes are particularly high for Switzerland, whose financial sector accounts for about 9 per cent of GDP and remains one of the world’s biggest centres for cross-border private wealth. In a letter to Swiss justice minister Beat Jans seen by the FT, the wealth managers’ association warned this week that Switzerland was creating an “extremely attractive target for cyber criminals” by collecting highly sensitive ownership information in a central database. Vivien Jain, the association’s chief executive, told the FT the new register should be paused for an official security assessment following the attack in Liechtenstein. “The reputation of our financial centre is at stake,” she added.

The SBA had similarly expressed concerns about the register’s safety, said multiple people familiar with the situation.