On Wednesday, the US Senate Finance Committee accused Swiss bank Credit Suisse of complicity in an ongoing conspiracy to aid wealthy Americans to evade taxes, despite an earlier promise to crackdown on the practice.

In 2014, Credit Suisse pleaded guilty to criminal charges that the bank had helped rich US clients avoid paying taxes by hiding assets in offshore accounts. The bank had agreed to crack down on such cases in the future as part of its settlement of the charges.

Now the committee alleges that after a two year investigation, it has found the bank failed to follow through on its pledge.

Now the committee claims its investigation has discovered “major violations of that plea agreement, including a previously unknown, ongoing and potentially criminal conspiracy involving the failure to disclose nearly $100 million in secret offshore accounts belonging to a single family of American taxpayers.”

According to their report, the committee has discovered more than $700 million in concealed wealth the bank was complicit in hiding in violation of the 2014 plea agreement.

Senate Finance Committee Chairman Ron 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 United States. This investigation shows Credit Suisse did not make good on that promise.”

Earlier this month, Credit Suisse was rescued by the Swiss government, which brokered a buyout by larger rival UBS, following a series of scandals and regulatory failures the bank had endured over the prior year, which culminated in a record level of outflows as it began to appear the bank was in trouble. UBS paid roughly $3.25 billion in the takeover, receiving additional support and backing from the Swiss government and central bank in the deal.