Spain’s national court on Monday ordered the release of Hugo Carvajal, the former intelligence chief of Venezuela, after it rejected an American request to extradite him to the United States to stand trial on drug trafficking charges.

Mr. Carvajal, known by the nickname “El Pollo,” or “The Chicken,” in Venezuela, was detained in Madrid in April on an arrest warrant issued by the United States that accused him of facilitating drug trafficking, as well as providing illegal support to the FARC rebel group in Colombia.

The court will publish its reasoning for rejecting the extradition request on Tuesday, but Mr. Carvajal’s release comes into force immediately, according to an official from the national court who asked not to be named ahead of the formal ruling.

The United States Justice Department alleges that in April 2006 Mr. Carvajal coordinated the transportation of 5,600 kilograms, or about 6.2 tons, of cocaine from Venezuela to Mexico that was bound for America, according to charges filed in federal court in New York.