The ex-chairman of the banking group has explained his thinking about the Swiss private bank that HSBC purchased in the late 1990s.

The former chairman of UK/Hong Kong-listed HSBC has told UK lawmakers that the bank should have made more checks before buying the Swiss private banking business that has been accused of holding money from tax evaders, media reports said.

"With the benefit of hindsight, it would have been better to have drilled into the detail much earlier. We didn't get everything right," Stephen Green told the House of Lords Economic Affairs Committee today. 

Green, who was HSBC’s chief executive from 2003 to 2006, and then chairman until 2010, was quoted as saying that neither he nor any senior managers know of the problems at the Swiss bank, which is headquartered in Geneva. The Swiss banking business was acquired in the late 1990s from Republic New York.

In March, various news organisations, including the International Consortium of Investigative Journalists, claimed that a cache of thousands of accounts that had been leaked from the Swiss bank showed that some of them were allegedly dodging taxes. HSBC said at the time that it had closed a large percentage of these accounts and that it had put in place new measures since 2008. The bank also carried full-page newspaper messages apologising for the saga.

Data covering a period from 2005 to 2007 was taken from the bank by former employee Hervé Falciani, whom Swiss authorities wish to put on trial because his behaviour is a serious crime under Switzerland’s bank secrecy laws.

Asked about these matters and the acquisition of the Swiss bank, Green said: “With the benefit of hindsight – and this was complicated by Swiss law which prevented [HSBC’s board] seeing client details – it would have been good to know details of this earlier and we didn’t get everything right.”