Police in Colombia have captured the man they regard as the country's top drug baron, Diego Montoya.
The US offered $5m for information leading to Montoya's arrest
He was arrested in his home province of Valle del Cauca.
Mr Montoya - known in Colombia's underworld as the "boss of bosses" - appears on the US Federal Bureau of Investigation's "10 Most Wanted" list.
He is accused of producing tons of cocaine for the US market. Officials say he helped found the Norte del Valle cartel based near the city of Cali.
The BBC's Jeremy McDermott in Bogota says Mr Montoya's capture is a huge coup for the government and ends the reign of one of the legends of the Colombian underworld.
Mr Montoya, 49, was arrested with just two bodyguards and in the company of his mother, without the rings of security that have foiled attempted raids in the past.
A recent scandal in the armed forces revealed that the drugs cartel had infiltrated the military, ensuring that Mr Montoya was warned about operations against him.
With this early warning system dismantled, it appears one of the world's most wanted men was surprised as he relaxed with his family, our correspondent says.
The FBI says the Norte del Valle cartel receives help from left-wing guerrillas and right-wing paramilitary groups.
US authorities had offered a reward of $5m for information leading to Mr Montoya's arrest.
Colombia's Defence Minister, Juan Manuel Santos, said Mr Montoya controlled a vast trafficking network responsible for about 70% of the cocaine smuggled to the US and Europe.
Mr Montoya's private army of assassins, called Los Machos, was behind some 1,500 killings, Mr Santos said.
"Drug traffickers take note: This is the future that awaits you," the minister told a news conference.
It is expected that the Colombian authorities will begin proceedings to extradite Mr Montoya to the US, where he has been indicted on drug trafficking charges.
In July, Colombia extradited another alleged leader of the cartel, Luis Hernando Gomez Bustamante, to the US. He had been arrested in Cuba in July 2004 after entering on a false passport and was returned to Colombia earlier this year.