Aparecida Schunck, mother in law of the famous Bernie Ecclestone, was taken from her home in Interlagos, San Paolo, last Friday night, according to Brazilian news magazine Veja.
Her kidnappers are asking for a ransom of 120 million reais (£27.8m) specifically to be divided into four bags, for her return, the report says.
The 67-year-old is the mother of Ecclestone's wife, Fabiana Flosi, whom the entrepreneur married in 2012 - three years after meeting her at the Brazilian Grand Prix.
Ecclestone, 85, is the chief executive of the Formula One Group, which manages Formula One and controls the commercial rights to the sport, and part-owns Delta Topco, the ultimate parent company of the Formula One Group. is one of the most powerful men in sport.
A crackdown by police and the creation of a special anti-kidnap division has significantly reduced the number of kidnappings in the country.