Rafael Caro Quintero, a Mexican drug lord known as “the narco of narcos” and one of the FBI’s 10 most wanted fugitives, has been arrested in his home country, according to media reports. Mexican marines arrested the 69-year-old, reported El Universal and other news outlets that cited national security sources. In the US, the Associated Press said it confirmed the news with a Mexican navy official who could only speak on condition of anonymity. El Universal noted that the arrest occurred days after Mexico’s president, Andrés Manuel López Obrador, met Joe Biden at the White House. “This is huge,” White House senior Latin America adviser Juan Gonzalez said on Twitter. No other details were immediately available. Caro Quintero, from La Noria, Sinaloa, is perhaps best known as one of the co-founders of the Guadalajara cartel. The group’s heyday was in the 1970s and 1980s, when it primarily trafficked cocaine, heroin and marijuana from Mexico to the US. One of the group’s hitmen – or “sicarios” – was Joaquin “El Chapo” Guzman, who founded the violent Sinaloa cartel but is now imprisoned. Caro Quintero at one point was sentenced to 40 years in prison, over the kidnapping, torture and murder of a Drug Enforcement Administration agent, Enrique “Kiki” Camarena, in 1985. Caro Quintero believed Camarena was to blame for a raid on a marijuana plantation the previous year. In 2013, a Mexican appellate court ruling set Caro Quintero free after he had served 28 years. US authorities and Mexican prosecutors were outraged. The supreme court reversed the decision. But Caro Quintero had gone into hiding. US officials have since accused him of assuming a leadership role in the Sinaloa cartel after El Chapo’s downfall while also running his own organization in the same region. Mike Vigil, the DEA’s former chief of international operations, said: “It is probably one of the most important captures of the last decade in terms of importance to the DEA.” Before Caro Quintero’s reported arrest on Friday, the US government was offering a reward of up to $20m for information leading to his capture. Caro Quintero, who last year lost a final appeal against extradition to the United States, will be extradited as quickly as possible, another Mexican official said. While the 69-year-old Caro Quintero is no longer considered a major player in international drug trafficking, the symbolic impact of his capture is likely to be significant on both sides of the border. Mexican security expert Alejandro Hope said the arrest pointed to significant cooperation between the two countries despite recent clashes over security. “This type of capture is unthinkable without the participation of the DEA,” he said. Mexico’s unwillingness to extradite Caro Quintero to the United States prior to his release from prison had always been a source of tension between the two countries. A US official said Washington was very eager to have him extradited. “This will hopefully start to mend the frayed relationship between the United States and Mexico in terms of combating drug trafficking,” said Vigil.