But the crash that killed Mr. Pereira dos Santos has awakened a debate over wealth, influence and traffic deaths, similar to a Chinese case in 2010 in which the son of a powerful official struck a poor farm girl, stirring an outcry.

Brazil has made strides in reducing its income inequality, lifting 40 million people into its middle class in recent years, but it still ranks among the most unequal of nations.

“I don’t understand why rich parents encourage their young and inexperienced children to drive machines incompatible with our roads,” said Ruth de Aquino, a columnist at the magazine Época, in an essay about Thor Batista. “We’re not in Germany; we don’t have autobahns.”

Cléber Carvalho Rumbelsperger, the lawyer for the victim’s family in this case, said in the days after the crash that witnesses contended that Mr. Pereira dos Santos was hit on the shoulder of the highway when Mr. Batista was trying to pass a bus. But Mr. Batista and his father each presented a starkly different version of what happened.

“The cyclist’s carelessness could have caused three deaths,” said the elder Mr. Batista, 55, in a Twitter message a day after Mr. Pereira dos Santos was buried. He said that both his son and a friend riding in the two-seat McLaren could have been killed.

Using a new account publicized by his father, who has almost 700,000 followers on Twitter, the younger Mr. Batista also took to the Web site. He posted dozens of messages, contending that Mr. Pereira dos Santos had been in the highway’s left lane. He also said that he was driving within the speed limit, while boasting of his skills as a motorist.