U.S. federal agents have detained two members of Venezuelan President Nicolas Maduro's family in Haiti, according to a Drug Enforcement Administration source who participated in the arrest.

The two men, identified as Efrain Antonio Campo Flores and Francisco Flores Freites, were arrested Tuesday night in the Haitian capital of Port-au-Prince as they were preparing to finalize a deal that would have allowed them to transport 800 kilograms of drugs to the United States, the source said.

    One of the men was raised by Venezuelan first lady Cilia Flores; the other is her nephew.

    Information about the arrest was corroborated by Mike Vigil, a former chief of international operations for the Drug Enforcement Administration who has contacts that are high-level federal law enforcement officials.

    During the arrest, both men had Venezuelan diplomatic passports and openly identified themselves as the son and nephew of Flores, maintaining that they had diplomatic immunity, Vigil said.

    Haitian authorities were asked about the arrest, but officials there said they were not involved in the raid. The Venezuelan government has not responded to requests for comment.

    Maduro and Flores married in July 2013, several months after he was sworn in as Venezuela's President on the heels of the death of longtime leader Hugo Chavez.

    But they'd been a couple for years, and both of them were members of Chavez' inner circle. During Chavez' final years in office, Maduro was vice president and foreign minister; Flores was the attorney general.