Credit Suisse and HSBC, two of the world's largest wealth managers, dismissed on Tuesday suggestions they were actively using offshore structures to help clients cheat on their taxes.
Their comments came a day after a leak of four decades of documents from a Panamanian law firm that specializes in setting up offshore companies showed widespread use of those instruments by global banks on behalf of their clients and triggered a raft of government investigations across the world.
The so-called "Panama Papers", revealed through an investigation by the International Consortium of Investigative Journalists (ICIJ), exposed financial arrangements of politicians and public figures including friends of Russian President Vladimir Putin, relatives of the prime ministers of Britain, Iceland and Pakistan, and the president of Ukraine.
Credit Suisse CEO Tidjane Thiam, who is aggressively targeting Asia's wealthiest for growth, said his bank was only after lawful assets.
"We as a company, as a bank only encourage the use of structures when there is a legitimate economic purpose," Thiam, who took the helm at Switzerland's second-largest bank last year, told a media briefing.
Separately, HSBC said the documents pre-dated a thorough reform of its business model.
"The allegations are historical, in some cases dating back 20 years, predating our significant, well-publicized reforms implemented over the last few years," said Gareth Hewett, a Hong Kong-based spokesman for HSBC.