Peruvian police have arrested Jacinto Nicolas Fuentes German, who is suspected of being a leader of Colombia's Urabenos criminal gang, BBC News said.
Peruvian officers detained Mr Fuentes in Lima, after a joint intelligence operation with Colombia, Peru's police chief, Gen Raul Salazar said.
Mr Fuentes, known as Don Leo, entered Peru illegally last month, they added.
The Urabenos gang controls much of the drug trade in northern Colombia, with many ex-paramilitaries in its ranks.
According to the Colombian authorities, Mr Fuentes took over running part of the Urabenos after one of the most wanted drug dealers, Henry de Jesus Lopez, was arrested in December in Argentina.
Mr Fuentes had been in prison in 2008 after being arrested with a group of armed men, but was subsequently released, Colombian media reported.