The Senate Finance committee has found new evidence that the Swiss bank is failing to follow the rules with dozens of account holders breaking US tax rules, despite a multimillion pound fine for facilitating tax evasion in 2014.

Based on the committee’s findings, the total amount concealed in violation of Credit Suisse’s 2014 plea agreement is more than $700m.

This follows a two-year investigation into Credit Suisse’s compliance with a 2014 plea agreement over tax evasion by thousands of the bank’s US customers.

Now owned by UBS following a rescue deal, Credit Suisse has admitted that it has identified 23 bank accounts held by wealthy Americans with deposits in excess of $20m, held offshore in overseas accounts which have not been disclosed to US tax authorities. It is still investigating further accounts with a risk more could be identified.