Police in Brazil have detained a Credit Suisse director in a federal inquiry as he tried to leave the country.
Credit Suisse says its investment arm is not in the spotlight
Six other company executives are under investigation as part of "Operation Switzerland" but Credit Suisse says the unit under scrutiny is a trade office.
It says Credit Suisse Representacoes is part of a Credit Suisse private banking division, but is non-financial itself.
Police want to know if executives illegally moved large sums of money overseas for Brazilian clients.
Investigating officers said Peter Schaffner, a Swiss national, was detained while trying to leave Brazil for Switzerland on Thursday.
He is being held at the headquarters of Sao Paulo's federal police.
Credit Suisse confirmed a company employee was in the custody of Brazilian authorities, but that the firm had not been told of any charges against him.
Alex Leon Ades, one of Mr Schaffner's three lawyers, said it was "a very delicate case with major repercussions".
Of the other six three are Swiss, one is Swiss-Portuguese and two are Brazilians. They had their passports removed under a judicial order and are prevented from leaving Brazil while authorities investigate, police said.
Credit Suisse has said the investigation focuses on its Brazilian private banking unit for wealthy clients, not on its investment banking business.