The bank is the subject of regulatory probes at home and abroad following the BBC Panorama programme’s allegations that it helped clients dodge tax.
Chairman Douglas Flint and group chief executive Stuart Gulliver (pictured) were grilled by the Treasury Select Committee on Wednesday following weeks of criticism.
The pair apologised for the “unacceptable” practices, which they said had caused “damage to trust and confidence” in the company.
When asked about the list of allegations and investigations into HSBC by international regulatory authorities Flint said: “It’s a terrible list,” according to the BBC.
He said he could not rule out the possibility of more problems emerging from the bank, but added reform is “ongoing”.
Gulliver also denied any wrongdoing when it came to light he held £5m in a Swiss bank account through a company based in Panama. He told the committee he had “followed the letter of the law” of the UK non-domicile rules, and had only taken steps to protect his privacy and prevent other HSBC staff seeing details of his pay.
Earlier this week, in its full-year results, Flint said the bank “deeply regrets” the practices within its Swiss private bank and plans to sell off parts of the business following disappointing 2014 results.
The results revealed pre-tax profits fell 17% last year to $18.7bn (£12.1bn), compared with $22.6bn in 2013.
