Williams could be lining up a replacement for its struggling race driver Robert Kubica.
Brazil's UOL reports that Sergio Sette Camara, currently fourth overall in Formula 2, has backing for the role by his sponsor Petrobras.
Petrobras, a Brazilian oil company, currently sponsors McLaren, where the 21-year-old is a test driver.
But when asked if McLaren uses Petrobras fuel, team boss Andreas Seidl said: "We use the same fuel (BP Castrol) as our engine supplier (Renault)."
UOL said Petrobras denied that it is in talks with Williams, its former F1 partner.
