The bank confirmed that a Swiss employee in its wealth management division had been detained in the investigation which is targeting Credit Suisse and AIG, as well as UBS.
It is alleged that some Brazilian companies are avoiding taxes by laundering money through Swiss banks and the US insurance group, according to the Brazilian federal police.
Reports in the Times state that Clariden Leu, a private banking arm of Credit Suisse, have confirmed that one of their employees has also been detained.
UBS said they were looking into the matter and Credit Suisse did not comment while AIG said it was "not aware of any wrongdoing by any AIG employee".
Brazilian police claim to have recovered over $4 million in cash during the raids on 44 sites across the South American country.
No one has been charged over the claims and Brazilian law permits them to be held for five days without charge.