About $16m in cash and luxury watches were intercepted from a delegation with Teodorin Nguema Obiang, the vice president of Equatorial Guinea.
Teodorin is also the son of Teodoro Nguema Obiang Mangue, the country’s president.
Estadao reports that Brazil’s federal police seized the cash and watches after searching their private plane which arrived at the Viracaspos airport near Sao Paulo on Friday.
About $1.5m cash was found in one bag and $15m worth of luxury watches was found in another bag.
Brazilian law prohibits people from entering the country with more than 10,000 reais ($2,424) in cash.
According to Estadao, an official of the Equatorial Guinea Embassy in Brazil, who was with the delegation at the time, the money was for Teodorin’s medical treatment and hotel expenses during his stay in Brazil.
The official, the report added, said the luxury watches, engraved with Teodorin’s initials were for his personal use.
Teodorin’s belongings were not searched as he was the only one with diplomatic immunity among the delegation.
Teodorin has been accused of embezzlement of public funds, using it to fund a lavish lifestyle. In 2017, he was sentenced to a three-year suspended sentence on charges of embezzlement of public funds and money laundering.
Teodorin’s father Teodoro has ruled Equatorial Guinea for about 39 years.