The man widely called the true winner of Venezuela’s tainted presidential election said on Tuesday that his son-in-law had been kidnapped by hooded men in Caracas, the capital.

Edmundo González said that his son-in-law, Rafael Tudares, was walking Mr. González’s grandchildren to school when he was “intercepted” by hooded men dressed in black, and taken away in a gold van.

“At this time he is missing,” he wrote on X.

The reported kidnapping comes one day after Mr. González met at the White House with President Biden, whose administration recognizes Mr. González as president-elect, in an effort to put international pressure on President Nicolás Maduro, the longtime authoritarian leader who claims he won Venezuela’s July election.

On Monday the Maduro government, in a statement, called the meeting “a flagrant violation of international law and a crude attempt to perpetuate imperialist interference in Latin America.”

Mr. González, 75, was forced to flee the country shortly after millions of Venezuelans voted for him, and he is now living in exile in Spain. He has promised repeatedly to return to his country to be sworn in on Friday, when Maduro, in power since 2013, is scheduled to be inaugurated for another six-year term.

The Maduro government has imposed a $100,000 bounty on Mr. González and he likely faces arrest if he returns.

The Venezuelan government has unleashed a wave of repression against anyone who challenges its declared victory, arresting about 2,000 people and charging most with terrorism. Human rights groups have described it as Venezuela’s most brutal campaign of repression in recent decades.

The government has released hundreds of those prisoners in recent months, in what many analysts saw as a signal to President-elect Donald J. Trump that it is willing to ease up on human rights in exchange for favorable treatment.

The U.S. State Department called the disappearance an attempt to “intimidate Venezuela’s democratic opposition.”

A spokesman for the Maduro government did not immediately respond to a request for comment.

Diosdado Cabello, a top official in Mr. Maduro’s government and one of his most powerful allies, did not refer directly to the episode in public remarks on Tuesday, but said, “today we have just dismantled a very dangerous group” of “foreign mercenaries from the United States and Colombia.’’

Mr. Tudares’ wife, Mariana González, said in a statement that her husband was a victim of “persecution.”

“At what point did it become a crime to be Edmundo Gonzalez Urrutia’s family?” she said.