Bogota (AFP) - One of Colombia's most notorious drug lords was extradited Wednesday to the United States to face drug trafficking charges, announced President Ivan Duque.

"I want to reveal that Dairo Antonio Usuga, alias 'Otoniel' has been extradited," Duque said on Twitter, calling him "the most dangerous drug trafficker in the world."

Usuga, 50, was the most wanted person in Colombia until he was arrested last October in the northwest of the country after a massive military operation.

Duque described Usuga as a "murderer of social leaders and police, an abuser of boys, girls and teenagers."

"Today legality, the rule of law, the security forces and justice triumphed," he added.

On Wednesday afternoon, a convoy of five bulletproof police vehicles transported Usuga from a prison in the capital Bogota to a military airport, where he was handed over to US Drug Enforcement Administration officials.

Images shared by local media showed a handcuffed Usuga seated in an airplane alongside Colombian police and an Interpol official.

Usuga was the leader of Colombia's largest narco-trafficking gang, known as the Gulf Clan.

He was captured near the border with Panama following a military operation involving 500 soldiers backed by 22 helicopters, in which one police officer was killed.

His arrest was one of the biggest blows to Colombia's drug trafficking business since the assassination of Pablo Escobar in 1993.

Usuga was indicted in 2009 in the United States, which had offered a $5 million bounty for information leading to his arrest.

The United States accuses Usuga and the Gulf Clan of illegally bringing at least 73 tons of cocaine into the country between 2003 and 2012.

Following Usuga's arrest and that of another 90 suspected gang members, Duque declared the "end" of the Gulf Clan.

However, four Colombian soldiers were killed in attacks blamed on the gang just days after Usuga's arrest.

The Gulf Clan was believed to be responsible for 30 percent of cocaine exports from Colombia, the world's largest producer and supplier of the drug.

'Who is afraid of Otoniel?'

Since his capture, Usuga has been held in a high-security prison in Bogota, and has been at the heart of multiple controversies.

Recordings of testimony "Otoniel" gave to the Truth Commission -- an extrajudicial body investigating the decades-long conflict between the government and the Revolutionary Armed Forces of Colombia (FARC) -- were stolen, the perpetrators unknown.

Colombian police also halted one of Usuga's Truth Commission hearings, saying the Gulf Clan had organized an escape attempt.

"Who is afraid of Otoniel?" read a headline on Cambio, an independent online news outlet, which charged that some people in the Colombian government sought to silence the drug lord.

The site reported Usuga would have said during his hearings that the army continued to work in complicity with right-wing paramilitaries in some parts of the country.

Citing a leaked Truth Commission document, the outlet said "Otoniel" had implicated 63 people as linked to the Gulf Clan, including a former minister, a former national director of intelligence, six former governors and four former members of parliament.

Family members of Usuga's victims had asked for the courts to suspend his extradition, arguing that he should stand trial in Colombia for "crimes against humanity."

But the Colombian justice system ultimately gave the green light for his extradition, Usuga's defense team told AFP.

Duque vowed that Usuga would still face justice in Colombia. 

"This criminal was extradited to serve drug trafficking sentences in the United States," the president said.

"But I want to be clear that once those are served, he will return to Colombia to pay for the crimes committed against our country."