After a week of damaging headlines for HSBC, its CEO has issued an apology concerning its alleged aid for tax dodgers via its Swiss bank.

The chief executive of Hong Kong/London-listed banking group HSBC, Stuart Gulliver, has apologised to the public in newspaper messages following fresh revelations about the bank’s alleged support for tax evaders via its Swiss unit.

Gulliver gave his “sincerest apologies” and said the revelations had been a “painful experience”. The CEO of one of the world’s biggest banks wrote the comments in full-page advertisements in newspapers on Sunday.

“Since 2008, our Swiss private bank has been completely overhauled,” he said. “We have absolutely no appetite to do business with clients who are evading their taxes or who fail to meet our financial crime compliance standards,” he said.

The bank was at the centre of a blaze of hostile media and political commentary last week after a BBC Panorama television documentary explained how the bank’s Swiss unit had helped thousands of individuals evade taxes. The claims had been made with the support of the Washington DC-based International Consortium of Investigative Journalists. The actual data on which the claims were based had been taken by a former employer, Hervé Falciani, between 2006 and 2007. (A trial of Falciani in a Swiss court is ongoing.)

While bank secrecy remains legal in Switzerland, HSBC, along with other banks, has suffered a reputational hit from operating banking in the country, although it said last week that since 2008, it has dramatically changed its operations and sharply reduced the number of clients and their assets run through Switzerland.

The affair raises further question marks not just about the kind of private banking that is now acceptable in the eyes of global regulators and national governments, but also about whether policymakers accept, or even understand, the need for a distinction between legitimate privacy and secrecy. It also highlights how some governments no longer see any major legal distinction between tax evasion and avoidance.