The Pope has called on individuals and institutions to play their part in ridding the world of the "disgusting vice" of human trafficking and prostitution.
He called the sex trade a "disease of humanity" as he described the "humiliated, afflicted and suffering women" he had met in a house run by the Pope John XXIII Community for victims of human trafficking.
The comments were made in his foreward to a new book on the subject, Women crucified: The shame of human trafficking as told from the street, written by Fr Aldo Buonaiuto, who is a priest in the Pope John XXIII Community.
He said that the women he met at the home were "truly, women crucified ... some of them with their child in their arms".
He recalled how, following the visit, he had felt the need to "ask forgiveness for the real tortures they had to endure because of their clients, many of whom call themselves Christian".
He praised the rescue and rehabilitation work being done by Fr Aldo, as well as his new book, saying it was necessary to tell the stories behind the "shocking numbers" of people being trafficked into the sex trade for "illegal and shameful profit".
"A person can never be offered for sale," he wrote, adding that the sex trade was "torturing" defenceless women.
He concluded with a call for individual and corporate action.
"Individuals and institutions cannot remain indifferent before their cry of pain," he said. "No one should turn away or wash their hands of the innocent blood that is shed on the roads of the world".