Brock Franklin
Brock Franklin, 31 Colorado's 18th District Attorney's Office

A Colorado man was given the longest sentence for human trafficking offences in US history when a judge jailed him 472 years.

Brock Franklin, 31, was considered by authorities to be the leader of a criminal ring that forced women and girls into prostitution. He was found guilty of 30 charges relating to the crime ring along with six other people earlier this year in a case brought under a Colorado law tackling organised crime in 2015.

"He took so much from me, and I'm still fighting to get it back," one of the victims said during Franklin's sentencing. "You have no idea the damage he has caused to the other women and myself."

But she added: "I am a survivor. I am free from the abuse...I hope he never sees the light of day outside the prison walls." Prosecutors had asked for 616 years but were said to be satisfied with the sentence.

Franklin was said to have used physical violence against women and girls when forcing them into prostitution. He also controlled them with drugs and forced them to sleep with him. The victims were then pimped out at local hotels.

"Today's historic sentence sends the resounding message that traffickers will be held accountable by Colorado law enforcement, prosecutors, and judges," said Colorado attorney general, Cynthia Coffman.

"This defendant used violence, drugs and manipulation to control his victims, including innocent children. The survivors in this case were incredibly brave to stand up and have their voices heard, and I am grateful they can now feel safer knowing that he will stay in prison for the rest of his life."

The case was brought with the cooperation of five women and three girls but authorities believe there were more victims.

"Any sentence that treats these women as individuals, and not as disposable pieces of property like the defendant did, is enough," said deputy district attorney Kelley Dziedzic, who prosecuted the case with assistant attorney general Janet Drake.

"More than anything, what we are pleased to see is a sentence that reflects the extraordinary work that law enforcement put into this investigation, and the extraordinary courage shown by each woman," she added.