Guilherme Montassier

Senior Associate
Consultant Senior
New York
+1 917 756 9867


Guilherme Montassier is a Senior Associate at FRA with over four years of accounting and forensic accounting experience.

Since joining FRA, Guilherme has performed detailed analyses on multiple matters, including investigating an alleged tax fraud scheme by analyzing key financial metrics in tax returns spanning over 20 years to identify potential evasion of excise taxes due to transactions with disqualified persons. Guilherme has also been involved in a gain calculation related to a DOJ and OFAC investigation in the tobacco industry. His work included in-depth review and analysis of complex contracts and agreements relevant to the allegations.

Guilherme has been involved in an investigation concerning the unravelling of multiple alleged fraud schemes of funnelling over $1b of debt through related parties, related to a financial services entity based in the Middle East. Guilherme provided litigation support to assist those affected by the alleged fraud with recovering assets and with reparations of damages.

Most recently, Guilherme has been involved in a gain calculation matter involving the Brazilian Controladoria Geral da União (CGU), where his work has included in-depth reviews and analyses of accounting documents, disgorgement and fines calculations for settlement proposals with the Brazilian authorities and assisting in meetings and conversations with local Counsel and authorities.

Prior to joining FRA, Guilherme worked as an accountant for an international logistics company and as an Associate in Ernst & Young’s Forensics Department in Rio de Janeiro, Brazil.

While at Ernst & Young, Guilherme gained valuable experience assisting clients with compliance due diligence, performing M&A risk assessments and supporting financial statement audit teams through manual journal entry analysis. His experience stretches across numerous industries, including financial services where he spent a majority of his time supporting a major investment bank.

Guilherme has been involved in different levels of media searches, assisting with discovery and vendor transaction testing to extract information for investigations and risk assessment due diligences.

Guilherme holds a Bachelor of Science in Accounting from the Federal University of Rio de Janeiro, and is a Certified Accountant in Brazil through the Federal Accounting Council.

Guilherme is a native speaker of Portuguese, with working knowledge in Spanish. He has lived in Brazil and he has been living in the United States since 2018. Guilherme is based in FRA's New York office.

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