Both nephews of Venezuelan President Nicolás Maduro's wife, Cilia Flores, pleaded not guilty on Thursday to their U.S. drug trafficking case.

Franqui Francisco Flores de Freitas, 30, and Efrain Antonio Campo Flores, 29, presented their pleas in Manhattan's federal court, five weeks after they were arrested in Haiti, Reuters reported. A U.S. law enforcement source said that in October, the two met an informant of the U.S. Drug Enforcement Administration, or DEA, in Honduras for assistance in transporting 800 kilograms (1,764 lb) of cocaine to the United States through an airport in Roatan, a Honduran island.

The indictment also indicated that Flores' nephews was involved in the same month in meet-ups in Venezuela for a shipment of cocaine, which was to be sent to the U.S. by way of Honduras as well, the news outlet noted.

The duo's drug trafficking case was the latest in a chain of enforcement investigations and actions conducted by U.S. authorities against individuals associated to the Venezuelan government, Reuters wrote.

According to Reuters, Flores is referred to by Maduro as the "First Combatant" and is a highly influential figure in her husband's administration. She was a part of the legal team of late socialist leader Hugo Chavez and secured his 1994 release from prison after an unsuccessful coup attempt.

People with knowledge of the proceedings also revealed that U.S. prosecutors are about to expose drug trafficking charges against Nestor Reverol, the head of Venezuela's National Guard, and Edylberto Molina, currently a military official stationed in Germany, Reuters added. Reverol, the former leader of Venezuela's anti-narcotics agency, would be among the top Venezuelan officials about to be slapped with U.S. drug charges.

In November, U.S. Congress members said that the arrests of Maduro's nephews are proof of his administration's corruption.

"The level of corruption and impunity has reached the highest circles of power there and I'm pleased it is now getting international scrutiny," said Sen. Robert Menendez, a member of the Senate Foreign Relations Committee, according to a statement issued to Fox News Latino.

Rep. Ileana Ros-Lehtinen, a Florida Republican who is chairwoman of the House Committee on Foreign Affairs, seconded Menendez's statement. According to Ros-Lehtine, this is not the first time that members of Maduro's relatives have been in "legal trouble due to their close connections to the illicit drug trade," the news outlet added.

Maduro has denied the charges against the two and insisted that the issue is just a smear campaign against the Socialist Party, Reuters wrote.

The U.S. State Department has said that over half of the cocaine made in Colombia is moved through Venezuela for markets in the U.S. and Europe, Reuters noted.