The survey of more than 28,000 staff from 22 banks and building societies across the UK found that a similar number saw instances of unethical behaviour being rewarded in their organisation.
Over a quarter of respondents, however, were worried about negative consequences if they raised concerns about the way their organisation works, with a fifth stating that people in their organisation turn a blind eye to inappropriate behaviour.
Despite the concerns about flexible ethics and not addressing bad behaviour, only 1% of respondents said the people in their organisation did not have the skills and knowledge to do their jobs well.
Commenting on the report, Simon Culhane, chief executive of the Chartered Institute for Securities and Investment (CISI), said: “Ethics is, by its very nature, flexible.
"Ethical standards are not rules set by compliance, but guidance for situations when the way forward may not be obvious. Differing responses when faced with these grey areas is not a phenomenon exclusive to bankers.”
Citing the CISI 'Speak Up' initiative launched in 2014, which aims to give employees the tips and tools to be confident raising workplace concerns, Culhane said: “Having a ‘listen up’ culture, where managers actually listen to concerns and employees know that they will be heard and supported, is best.
“The Financial Conduct Authority and Prudential Regulation Authority whistleblowing rules, designed to encourage a culture in which individuals working in the industry feel comfortable raising concerns and challenge poor practice and behaviour, came into force in September 2016.
“The BSB report suggests that the rules have, so far, had little impact in helping employees feel supported and confident enough to Speak Up.”