Credit Suisse Group is still helping wealthy Americans in evading taxes from the US Internal Revenue Service (IRS) even after reaching a plea deal with the US Department of Justice (DOJ) in 2014, according to a finding by the US Senate Finance Committee.

The beleaguered bank assisted in concealing more than $700m from the government, found the two-year probe carried out by the panel chaired by US Senator Ron Wyden.

In its 2014 plea deal with DOJ, Credit Suisse confessed its involvement in helping Americans avoid taxes for years and agreed to pay $2.6bn fine in compliance with the country’s law.

However, the Senate Finance Committee found that Credit Suisse significantly violated the plea deal by failing to divulge around $100m in secret offshore accounts held by a family with dual citizenship in the US and Latin America, among others.

This could represent an ‘ongoing and potentially criminal conspiracy’.

The committee also said that Credit Suisse aided Dan Horsky, a US businessman who pleaded guilty in 2016, in hiding $220m from the US government.

The bank further identified 23 new undeclared accounts of affluent Americans each with more than $20m.

Wyden said: “Credit Suisse got a discount on the penalty it faced in 2014 for enabling tax evasion because bank executives swore up and down they’d get out of the business of defrauding the US.

“This investigation shows Credit Suisse did not make good on that promise, and the bank’s pending acquisition does not wipe the slate clean.”

The latest development comes shortly after UBS agreed to buy Credit Suisse in order to rescue the bank from collapsing.