I have been travelling to Medellin for nearly 20 years and during that time I have witnessed the city’s mutation from one of the murder capitals of the world to one of Colombia’s booming cities. Unfortunately the years of evil and greed have marked this city for life, and the beauty hides a violent and disturbing criminal underworld.

When Pablo Escobar was killed in 1993 the Medellin cartel was left without a boss – and most of the assassins, traffickers and foot soldiers were left without a job. But soon, criminal gangs started to appear to fill the gap.

La Oficina – or «The Office» – is one of the most notorious groups that sprung up. They started literally as an office where anyone could hire a hit man. Years later they developed into one of the biggest criminal organisations in the history of Colombia. Today «The Office» is not only involved in drug trafficking but also in extortion, prostitution and human trafficking.

The narcos have always had an appetite for beautiful women. Money has never been an obstacle for them and in a city used to the flow of easy money, everything has a price.

‘Biggest brothel in world’

Escobar himself was known for paying thousands of dollars to have sex with models, actresses and even television presenters. Prostitution is not new to Medellin. A Colombian man once told me that «if you put a roof over Medellin it would be the biggest brothel in the world».

When you are out in the city you realise why he said that. The back streets are full of prostitutes, both male and female. Many of them are incredibly young; smoking bazuco, a Colombian version of «crack».

The place looked like the end of the world. On the corner you could see the gang members looking around, controlling the barrios.

After Medellin was «pacified», tourists started to flock to the city looking for cheap drugs and for sex. Gangs like «The Office» realised the potential business they had in front of them.

Virgin girls

First they offer just girls, then for more money you could have underage girls and then the golden prize for those willing to pay: «virgin girls».

I met several victims of the gangs but most were too scared to go on the record. Only one of them agreed to speak to us. She lives in one of the poorest barrios in Medellin. Her name is Maruja. She is in her early 30s but looks older.

Her daughter is just 14 and the gangs have already warned her that they have somebody willing to pay lots of money for her daughter’s virginity. She has no means to move to another barrio.

She feels trapped. Incredibly, she tells me that she also was a victim of sexual abuse when she was young. «They will have to kill me if they want to take my daughter, my life was ruined and I don’t want them to do the same to her.»