The US has linked a top Venezuelan official to a cocaine-smuggling scheme, but the details are still murky

A US Drug Enforcement Administration agent testified on Thursday that an investigation of two nephews of Venezuela's first lady started after a drug trafficker cooperating with authorities reported a meeting arranged by her brother, a high-ranking police official.

The agent testified in Manhattan federal court about the origins of the probe of Franqui Francisco Flores de Freitas and Efrain Antonio Campo Flores as he detailed how two key informants deceived investigators to conduct drug deals.

DEA Special Agent Sandalio Gonzalez said in court that a cooperating witness, a well-known drug smuggler called El Sentado, told him in October 2015 that a Venezuelan official named Bladimir Flores said he was going to send his nephew to meet with El Sentado.

"He (cooperating witness) indicated that these individuals wanted to fly drug-laden planes to Honduras with flight plans," Gonzalez said.

Gonzalez did not provide further detail about the role of Bladimir Flores. He is believed to be the brother of Venezuelan first lady Cilia Flores and serves as inspector general of Venezuela's investigative police, known as CIPCP. Bladimir Flores could not be reached for comment by Reuters.

The testimony came during proceedings in which lawyers for Cilia Flores' nephews sought to suppress evidence against them and statements they gave after their November 2015 arrests, arguing that they were not properly informed of their rights.

Both men are fighting charges that they worked with others to try to send 1,763 pounds of cocaine from Venezuela to Honduras so it could be imported into the US.

In court, Gonzalez characterized the nephews as significant drug traffickers.

"They indicated they had the run of the main airport in Caracas and then could easily dispatch drug-laden planes on the presidential ramp," he said.

But under questioning by the nephews' lawyers, Gonzalez acknowledged a series of problems involving the DEA's reliance on El Sentado and two informants who at its direction posed as Mexican drug traffickers.

The informants lied throughout the probe about their own drug dealing and one used Venezuelan prostitutes the defendants paid for, he said. Both have since been charged and are incarcerated, he said.

Gonzalez also said El Sentado failed to record his first meeting with the nephews in October 2015, despite instructions to do so. Prosecutors said El Sentado was killed in Honduras last December.

Moreover, the implication of Flores' brother, a top law-enforcement official, seems to cast doubt on the portrayal of the nephews of the masterminds of the drug-smuggling scheme in question. While it's possible the nephews could've had influence over procedures at the Caracas airport, past investigations suggest that the military and national police keep tight control over what goes on there.

Insight Crime has suggested the nephews' involvement was political cover the role of the Cartel of the Suns, a trafficking organization that is believed to be made up of members of Venezuela's armed forces.

The nephews' case, an embarrassment for Venezuelan President Nicolas Maduro as Venezuela experiences political and economic struggles, was brought last year amid a series of US probes that have linked individuals connected to the Venezuelan government to drug trafficking.

Earlier this year, US prosecutors unsealed indictments against two high-level Venezuelan officials, accusing them of participating in an international cocaine-smuggling operation and taking bribes from drug traffickers.

The country's military has been accused of extensive involvement in the movement of drugs through the country to destinations in the US and Europe. Such allegations also extend to high-ranking government officials.

In the wake of the unsealing of the indictments early August, Maduro, the Venezuelan president, spurned the charges and appointed one of the officials charged, Nestor Reverol, to be interior and justice minister, a role that oversees the country's police forces.

(Reporting by Nate Raymond in New York; Editing by Peter Cooney)