Writing on Twitter, Santos added authorities would elaborate on the circumstances of the killing of Roberto Vargas Gutierrez, alias "Gavilan," who had been sought for a 500 million pesos ($170,000) reward.
First bar for the deaf opens in Colombia
The Gulf Clan, which accounts for some 70 percent of Colombia's cocaine production, was born from the remnants of an outlawed right-wing paramilitary group which fought rebels during the country's half-century civil conflict.
The paramilitaries were officially disbanded in 2006, but authorities say their members are still making money from drugs and violence.
Nine dead, 28 missing in Colombia tourist boat sinking
Its leader, Dairo Antonio Usuga, alias Otoniel, is the most wanted man in the country. The US has placed a $5 million bounty on him.
Colombia is the world's leading coca leaf grower and also the biggest source of cocaine, producing 866 tons in 2016, according to the UN.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ