The Brazil affiliate of accounting firm Deloitte Touche Tohmatsu agreed Monday to pay $8 million to settle a U.S. regulator’s allegations it issued false audit reports and tried to cover it up.

The fine for Deloitte Touche Tohmatsu Auditores Independentes, Deloitte’s Brazilian member firm, is the largest ever imposed by the Public Company Accounting Oversight Board, the U.S. audit-industry regulator. Twelve former Deloitte Brazil partners and other personnel were sanctioned as well in the case, which was announced Monday by the PCAOB.

In one instance, one of the Deloitte auditors told another that “everything we discussed, never happened,” according to the PCAOB.

In settling, Deloitte Brazil admitted it violated quality control standards and failed to cooperate with the PCAOB’s inspection and investigation. That is the first such admission by an affiliate of a Big Four accounting firm.

The PCAOB insisted on the admissions because “it demonstrates the seriousness, the egregiousness of what happened here,” said Claudius Modesti, the PCAOB’s enforcement and investigations director. The 12 employees settled without admitting or denying wrongdoing.