Swiss corporate governance foundation Ethos has dismissed a detailed attempt by UBS to defuse a row over its risk controls, and has demanded an independent, public investigation to restore confidence in the bank.

UBS, which last year lost Sfr4.4bn (€2.7bn) due to its exposure to sub-prime US mortgages, last week published a detailed, 36-page response to questions Ethos had asked in December about the bank’s risk management. This described how losses arose from extraordinary market developments and hedging strategies that worked less well than expected.