By CNN's Jonathan Wald
When Marius Nejloveanu was sent to jail in January for 21 years, it was the longest sentence anyone had faced in Britain for human trafficking.
The judge said the 23-year-old Romanian, together with his 51-year-old father, Bogdan, had run a sex trafficking ring like a family business.
They lured several women, then aged between 15 and 23 years old, from Romania to the brothels of Madrid and Manchester, where they forced them to work as prostitutes.
One of the girls was Marius Nejloveanu's cousin. Another was a relative of the Nejloveanus' business partner who pled guilty to sex trafficking.
Their closest family pled ignorance to Marius' crimes and protested Bogdan's innocence.
Outside their family home in the snow-swept town of Buzescu, Bogdan's mother Florica Nejloveanu angrily insists "my son is in prison for nothing, cause my little boy isn't guilty of anything."
Another of Bogdan's children and Marius' step-brother, Nicolaie, raises his hands defensively. "I don't know what my brother does. My brother doesn't tell me what he's up to," he says.
The detective who initiated the investigation into the Nejloveanus has a different view. "They are criminals," Stefan Florea says as he leans over the case file. "Marius, he is a liar. He is a guy like Casanova. He said to all these girls, I love you, I want to marry you, and when he and those girls went to Spain he forced them into prostitution," Florea said.
His words are grave but his tone is casual. Maybe it's because Florea is all too familiar with this kind of crime. He says he investigates between 10 and 20 human trafficking cases every year.
As I traced the origin of Marius and Bogdan Nejloveanu's offence, I was struck by how widespread human trafficking is and how common it is for offenders to traffick their own family members.
Romulus Ungureanu leads Romania's fight against trafficking as Director of the National Agency Against Human Trafficking.
"More than 80% of the victims being trafficked, they've reported on the way back that their recruiter was someone that they knew before or that they've met through a friend or a member of the family," Ungureanu says.
It may seem hard to comprehend how someone could enslave a friend or family member, but for some who rehabilitate victims of trafficking, the reason is straight-forward.
Iana Matei runs a safe house for girls who have been trafficked for sex.
"Traffickers simply don't feel they are doing anything wrong," Matei says. "Money is their God and worth making compromises for – so long as they are making money, it doesn't matter how they do it."
And so long as there is money to be made, trafficking is showing no signs of slowing down. "At the moment the biggest illegal trade in the world is drugs and number 2 is human trafficking," says Andrew Wallis, the head of anti-trafficking charity, UnseenUK.
"Everybody says that within five years it will be the biggest illegal trade in the world and the reason for that is with trafficking you have repeat business," he said. "So you can sell a person again and again and again and one woman can make up to £100,000 to £200,000 a year [approx. $170,000 - $270,000 a year], Wallis said.
The United Nations has called Romania "a hot spot" source of trafficking victims. The country's Anti-Trafficking Agency identified 1,154 victims in 2010 – an increase on the number in 2009 following a steady fall in the total for the 5 years before.
Although statistics can tell part of the story, Ungureanu cautions against becoming lost in them.
"This type of crime is a living type of crime and it is very important for everybody to understand that behind each number there is actually a name, a life story, there is a person," he says.
For Ungureanu, one of those names is Mirela Buju.
In 2009, at the age of 26, she was bought, sold for sex, murdered and left in a cellar by one of Romania's most notorious human traffickers, Armand Ceanac. Ceanac's mother and brother were also convicted for human trafficking.
Ceanac is serving a 25 year sentence – the longest in Romania for a crime related to human trafficking.
"I paid fifty dollars for her and took her to my home," Ceanac recalls from within Giugiu, a maximum security prison outside of Bucharest, where prison officials allow him to meet with CNN.
"One time I had a fight with her, I hit her and then I slept with her and the next morning she didn't wake up. Later on she died."
"I'm not just sorry," the 29-year-old Ceanac went on to say. "I would give my life to turn back time and bring her back. I wanted to be a wise guy but I completely failed. It was the greatest mistake of my life."
For Iana Matei, one of the names behind the numbers is Marcela.
Trafficked when she was 15, Marciela died from cancer of the uterus when she was 18.
Iana Matei says the doctors determined Marcela developed cancer after her traffickers repeatedly made her push a sponge into her vagina after each time she had sex.
"The worst part of it was at the end, when it was very clear that she was going to die, sometimes she was the one saying 'don't cry, maybe that was my fate,' and I think that this is what makes me so angry because I don't think that there is a fate who says that a child has to be born and basically used until it is broken and then dies," Matei said.
Marcela's picture sits on Iana Matei's desk and inspires her to ensure that no other girl suffers the same fate.
Matei isn't prepared to take any chances. She installed security cameras in the safe house to protect the girls from the traffickers, each other and even themselves. Post-traumatic stress has led to frequent suicide attempts, Matei says.
In 2008 Matei worked on one case in which all the girls involved in a sex trafficking ring in the city of Pitesti were rescued and slowly, but surely, are being rehabilitated.
One of the girls, who wished to remain anonymous described her experiences in captivity. "I saw one of them removing the eye of a girl because she wasn't making enough money," the girl said. "Another time I saw them cut another girl's leg. They were all afraid to run away or tell the police. When they weren't happy with us, they took us away into a house and tortured us."
After three months of research on this story, we found the term human trafficking fails to convey the horror of what victims like Mirela Buju or Marcela go through. It fails to convey the brutality inflicted by people like Armand Ceanac or Marius and Bogdan Nejloveanu.
"It's modern day slavery," Andrew Wallis says. "A couple of years ago we celebrated the end of the trans-Atlantic slave trade but slavery exists today.
The UN estimates up to 800,000 people a year are sold into slavery – these slaves have no rights, they are used and abused and exist only to make money for their owners."
– Jonathan Wald is a producer based at CNN’s London bureau. Dan Rivers and Cosmin Stan contributed to this report