Marco Rubio
Marco RubioReuters

One of Venezuela’s most powerful leaders may have put out an order to kill Florida Senator Marco Rubio, the Miami Herald reported on Sunday, citing intelligence obtained by the U.S. last month.

Rubio has been a fervent critic of Venezuela. The report noted that federal authorities couldn’t be sure at the time if the uncorroborated threat was real, but they took it seriously enough that Rubio has been guarded by a security detail for several weeks in both Washington and Miami.

Diosdado Cabello, the influential former military chief and lawmaker from the ruling socialist party who has publicly feuded with Rubio, is believed to be behind the order, according to the Miami Herald.

The death threat was outlined in a memo to several law enforcement agencies disseminated last month by the Department of Homeland Security. The memo, designated “law enforcement sensitive” but not classified, was obtained by the newspaper.

The memo revealed an “order to have Senator Rubio assassinated,” though it also warned that “no specific information regarding an assassination plot against Senator Rubio has been garnered thus far” and that the U.S. had not been able to verify the threat. The fact Cabello has been a vocal Rubio critic in Venezuelan media was also noted.

According to the memo, Cabello might have gone as far as to contact “unspecified Mexican nationals” in connection with his plan to harm Rubio.

The Venezuelan Embassy in Washington declined to comment. Venezuela’s Ministry of Communication and Information said Sunday it could not respond to media queries until Monday. Messages sent to some of Cabello’s email addresses were not immediately returned.

Rubio also declined comment through a spokeswoman. His office had previously sent reporters’ questions about the security detail to Capitol Police, which did not respond but has in the past also declined comment.

Capitol Police “is responsible for the security of members of Congress,” Homeland Security spokesman David Lapan said in a statement, adding, “It would be inappropriate for DHS to comment on the seriousness of the threat.”

The United States recently imposed sanctions against Venezuelan President Nicolas Maduro, freezing his assets in the U.S. and prohibiting Americans from dealing with him.

The move came come after the Maduro government held controversial elections for a National Constituent Assembly (ANC) that “aspires illegitimately to usurp the constitutional role of the democratically elected National Assembly, rewrite the constitution, and impose an authoritarian regime on the people of Venezuela,” the Treasury said in a statement.

The outspoken Maduro has insulted his political opponents as "heirs to Hitler" in the past, and has been frequently accused of anti-Semitism.

In 2014, he twice expelled American diplomats from Venezuela, claiming they were encouraging protests against him by opposition groups.