Officials hope that Salvatore Mancuso will cooperate by revealing information about hundreds of murders and forced disappearances.

Salvatore Mancuso arrived at Bogota’s El Dorado airport on Tuesday. Having seen several requests to be sent to Italy, where he also has citizenship, denied, he was quickly taken into police custody, with authorities hoping he would shed light on hundreds of crimes that took place during civil unrest in the 1990s and early 2000s.

Now 59, Mancuso, who arrived on a charter flight carrying dozens of Colombians deported after illegally entering the US, was formerly a leader of the United Self-Defense Forces of Colombia. The paramilitary group, founded by cattle ranchers, fought against left-wing rebels during one of the most violent stretches of Colombia’s decades-long armed conflict.

Human rights organisations and government officials hope that he will cooperate with the justice system and provide information about hundreds of crimes.

Mancuso has confessed his co-responsibility for numerous massacres. He has been in prison in the US since 2008 for drug trafficking, and has indicated he is now ready to take on the role of “peace advocate”.

“I come to continue with my commitments to the victims, but at the same time, I come to put myself at the service of a peace agenda that will prevent Colombia from being an eternal factory of victims and collective pain,” Mancuso said in a statement distributed to the media upon his arrival.

He will remain in prison in Colombia, where courts have judged him responsible for more than 1,500 acts of murder and disappearances. He will attempt to get a reduced sentence, and possibly a release from prison, from a transitional justice system created by Colombia’s 2016 peace deal.

Victims of the nation’s conflict are hoping that Mancuso helps shed light on hundreds of murders and forced disappearances carried out by paramilitary fighters, including extrajudicial executions in which victims were buried in mass graves.

In multiple hearings with Colombian judges, including some by teleconference while in US custody, the former paramilitary leader has spoken of his dealings with politicians, and of the potential involvement of high-ranking officials in war crimes.

But his extradition to the US in 2008 had slowed investigations.

“Mancuso’s return to the country must contribute to the construction of peace, justice, truth and the non-repetition of war,” said Rodrigo Londono, also known as Timochenko, a former leader of the left-wing Revolutionary Armed Forces of Colombia (FARC) rebel movement. He is the current chairman of the FARC political party Comunes.

“I extend my hand to Mancuso to reconcile the country and bring to light all the responsibilities of the armed conflict,” he wrote on social media. “Peace will win!”

Colombia suffered through nearly six decades of civil war waged between left-wing rebels, right-wing paramilitaries and the country’s military. The conflict killed more than 450,000 people and displaced millions.

FARC, the largest rebel organisation, signed a peace deal with the government and laid down its arms in 2016.

President Gustavo Petro, who took office in August 2022, has made pursuing “total peace” in the South American nation a key plank of his administration. He signed a landmark truce deal with The National Liberation Army (ELN) which was extended in early February.