Griselda Blanco, a convicted drug trafficker who was once known as the "Godmother" and the "Queen of Cocaine," has been shot to death by an unidentified gunman, police in Colombia said on Tuesday.

Colonel Mauricio Cartagena of Medellin's metropolitan police said on Tuesday that the 69-year-old was killed at a butcher shop in the city on Monday.

Cartagena said a man approached Blanco at the shop and fired before escaping on a motorcycle driven by another man. She died on her way to the hospital.