MADRID/WASHINGTON (Reuters) - Spanish police on Friday arrested Hugo Carvajal, a former head of Venezuelan military intelligence, who Washington believes has a “treasure trove” of details he is willing to share about Venezuelan President Nicolas Maduro.

FILE PHOTO: Venezuela's President Nicolas Maduro (R) embraces retired General Hugo Carvajal as they attend the Socialist party congress in Caracas in this picture provided by Miraflores Palace July 27, 2014. REUTERS/Miraflores Palace/Handout via Reuters/File Photo

Carvajal, a former general and close ally of the late Venezuelan leader Hugo Chavez, was arrested on drug trafficking charges on a warrant issued by the United States, a police spokeswoman said.

“He is, I would dare to say, the most knowledgeable person to now be outside of Venezuela and be willing and able to cooperate with ... a treasure trove of information,” the U.S. administration official said, speaking on condition of anonymity.

“He will clearly be cooperating with us. He’s expressed that publicly,” the official said.

A court spokesman said Carvajal would appear before Spain’s High Court on Saturday. The court needs to decide within 24 hours of his arrest whether he will be jailed pending a decision on his extradition or if he will be set free.

The U.S. Justice Department said it had asked Spain to extradite Carvajal to face cocaine-smuggling charges that were filed in 2011 and unsealed in 2014.

Carvajal, head of military intelligence from 2004 to 2008, denounced Chavez’ successor Maduro in February and gave his support to Juan Guaido, who in January invoked the constitution to become Venezuela’s interim president.

Guaido was later recognized by the United States and dozens of governments, but Maduro remains in office with support of the military and has denounced Guaido as a U.S. puppet.

Guaido has offered amnesty to military leaders who took his side.

Carvajal recently said on Twitter that he would relay all the information he knows to the appropriate authorities, the senior U.S. administration official said.

“We look forward to receiving that information and to learning everything he knows ... about how Maduro and his mafia operate,” the official said.

Washington expects to learn more about Maduro’s ties to Cuba, Lebanon’s Hezbollah, and Colombia’s National Liberation Army (ELN) and the Revolutionary Armed Forces of Colombia (FARC), the official said.

The arrest is “very bad news” for Maduro and will provide protection to Carvajal who “probably had a target on his head,” the senior U.S. administration official said.

SECOND ARREST

This was the second time Carvajal has been arrested on the U.S. charges, which allege that he coordinated the transportation of 5,600 kg (1,235 pounds) of cocaine from Venezuela to Mexico in April 2006. That shipment was bound for the United States, according to charges filed in federal court in New York.

Carvajal was arrested on the Dutch Caribbean island of Aruba in 2014, but the Dutch government accepted Venezuela’s argument that he had diplomatic immunity because he had been nominated consul to Aruba.

Carvajal also was sanctioned by the U.S. government in 2008 for “materially assisting the narcotics trafficking activities” of Colombia’s FARC rebel group.

The U.S. Treasury’s Office of Foreign Assets Control (OFAC) said Carvajal’s assistance to the Revolutionary Armed Forces of Colombia included protecting drug shipments from seizure by Venezuelan anti-narcotics authorities and providing them with weapons.

Carvajal also provided FARC with official Venezuelan government identification documents that allowed its members to travel to and from Venezuela, OFAC said.

In an interview with the New York Times published in February, Carvajal said any dealings he had with drug traffickers resulted from his role investigating them as intelligence chief.

Carvajal said he had met with FARC members in 2001 to engage them as a government negotiator in the kidnapping of a Venezuelan businessman, a trip that had been approved by presidents in both Venezuela and Colombia.