Kosuke Okahara, a 34-year-old freelance photographer whose decade-long documentation of Colombia's notorious drug gangs has earned him the 2014 Pierre & Alexandra Boulat Award for professional journalism as well as a prize of €8,000 (¥1.08 million), says he is determined to continue his work in the country.

"The story has not ended," Okahara said in September after winning the award for his project, entitled "Any Given Day," which attempts to describe the endless cycle of violence in the city of Cali, a cocaine production center with one of the world's highest homicide rates. "With the prize, I can go back."

One of his many photographic subjects from the region is a man in his mid-20s who claims to have killed at least 30 people.