MADRID (Reuters) - Hugo Carvajal, a former Venezuelan military intelligence chief who Washington believes has valuable information on President Nicolas Maduro, was jailed on Saturday by Spain’s High Court pending a decision on an extradition request to the United States, a court spokesman said.

A Civil Guard van believed to be carrying the former head of Venezuelan military intelligence, Hugo Carvajal arrives outside the high court, in Madrid, Spain April 13, 2019. REUTERS/Javier Barbancho

A former general and close ally of former Venezuelan leader Hugo Chavez, Carvajal was arrested by Spanish police on Friday on a U.S. warrant for drug trafficking charges.

Following Carvajal’s arrest, the United States hailed on Friday his possible collaboration as a potential boon in the fight against Maduro, who still retains control of the bulk of Venezuela’s armed forces and state institutions.

During the hearing, Carvajal denied links with drug trafficking and Colombia’s FARC rebel group and challenged his potential extradition to the United States, the spokesman said.

Carvajal will fight the U.S. extradition request on the grounds of having ties in Spain, where his family currently resides after traveling here before him.

Carvajal left Venezuela a month ago, traveling by boat for 16 hours to reach the Dominican Republic before flying to Madrid, he told the court.

The United States must now formalize its extradition request, which will be ruled upon by the High Court.

The U.S. Justice Department said on Friday it had requested Carvajal’s extradition on cocaine smuggling charges filed in 2011 and unsealed in 2014.

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

A U.S. administration official told Reuters on Friday that Carvajal has valuable information on Maduro and is willing to cooperate.

Carvajal denounced Chavez’s successor Maduro in February and backed Juan Guaido, who in January declared himself Venezuela’s interim leader.