Fernando Llano, File, Associated Press
FILE - In this Oct. 18, 2014 file photo, Venezuela's President Nicolas Maduro and first lady Cilia Flores, greet supporters as they arrive for a march for peace in Caracas, Venezuela. Two nephews of Venezuela's powerful first lady Cilia Flores were arrested in Haiti on charges of conspiring to smuggle 800 kilograms of cocaine into the U.S. and will be arraigned in New York, three people familiar with the case said Wednesday, Nov. 11, 2015.

BOGOTA, Colombia — Two nephews of Venezuela's powerful first lady Cilia Flores were arrested in Haiti on charges of conspiring to smuggle 800 kilograms of cocaine into the U.S. and will be arraigned in New York, three people familiar with the case said Wednesday.

The arrest Tuesday, coming just three weeks ahead of key Venezuelan legislative elections, is likely to exacerbate already tense relations between the U.S. and Venezuela and cast a hard look at U.S. accusations of drug trafficking at the highest levels of embattled President Nicolas Maduro's socialist administration.

The two suspects, Efrain Campos and Francisco Flores, were extradited from Haiti and scheduled to be arraigned Thursday in a federal court in New York, said a U.S. law enforcement official who insisted on anonymity because he wasn't authorized to discuss the case.

Michael Vigil, a former head of international operations at the Drug Enforcement Administration who was briefed by U.S. authorities about the lengthy undercover operation, said Campos and Flores were arrested in Haiti's capital, Port-au-Prince, after arriving from Venezuela aboard a private plane. Both men were carrying diplomatic passports even though they don't have diplomatic immunity, Vigil said.

He also said Campos had claimed to law enforcement that he is the son of Flores and stepson of Maduro.

Another person briefed on the incident, who agreed to talk about the case only if not quoted by name, said Campos is the son of a deceased sister of Flores and was partly raised by the first lady and Maduro.

Flores, who Maduro calls the "First Combatant," is one of the most-powerful members of Venezuela's revolutionary government and a constant presence alongside her husband whenever he appears in public. The two traveled this week to Saudi Arabia for a summit and she's expected to be with the president Thursday when he's scheduled to address the United Nations Human Rights Council at a special meeting in Geneva called at Venezuela's request.

A former president of the National Assembly who is now running for congress, Flores became romantically involved with Maduro in the 1990s while serving as lawyer for the then-jailed Hugo Chavez. Maduro was one of many leftist activists drawn to the charismatic junior army officer following his arrest for a failed 1992 coup attempt. The two formally wed in 2013 shortly after Maduro was elected.

Venezuela's Communications Ministry and Foreign Ministry declined to comment about the reported arrests, saying they had no information about the incident. Maduro and Flores didn't issue any comment, while the president's Twitter account highlighted his meetings in Saudi Arabia with leaders from the Middle East.

American prosecutors have been steadily stepping up pressure on high-ranking members of Venezuela's military, police and government officials for their alleged role in making the country an important transit zone for narcotics heading to the U.S. and Europe. The U.S. government says more than 200 tons a year of cocaine flows through Venezuela, about a third of Colombia's estimated production.

But while several Venezuelan officials, including a former defense minister and head of military intelligence, have been indicted or sanctioned in the U.S., and many more are under investigation, no drug probes had previously touched Maduro's inner circle.

The arrests come as Maduro's government is reeling from an economic crisis marked by triple-digit inflation and widespread shortages that have emboldened its opponents. Polls say Venezuelans could hand the ruling socialist party its biggest electoral defeat in 16 years in next month's legislative elections.

Michael Shifter, president of the Washington-based Inter-American Dialogue think tank, said Maduro might use the arrests as a pretext to postpone the elections.

"He will blame the arrests on U.S. imperialism and see them as an attempt to undermine his government," Shifter said. "The news could well eclipse some of the mounting, severe criticisms, including from the OAS (Organization of American States) secretary general and throughout the region, aimed at the regime's abuses against the opposition."

Shifter added that evidence tying high levels of Venezuela's government to drug trafficking are increasing, calling that "profoundly troubling."

Vigil said negotiations between the two arrested men and an undercover agent focused on getting a plane and pilot to fly the drugs to Honduras, a popular smuggling destination for cartels operating in Venezuela, for their eventual transport to the U.S.

The other person brief on the case said abundant photographic and video evidence was collected as part of the sting. Venezuela's consul in New York, Calixto Ortega, called the State Department on Wednesday to lodge a protest, the person said.

Associated Press writer Joshua Goodman reported this story in Bogota and AP writer Alicia A. Caldwell reported from Washington. AP writers Fabiola Sanchez in Caracas, Venezuela, Jacobo Garcia in Bogota and Tom Hays in New York contributed to this report.