Pastor Kerry Hilton and his wife, Annie, have rescued over 200 Indian girls from Kolkata's red-light district. The couple teaches the girls how to sew, and gives them jobs as seamstresses in their manufacturing company.

"We don't hire on the basis of experience or skill," Pastor Hilton told ABC News. "We hire on the basis of a need to be free."

The New Zealand couple was shocked to learn of India's billion-dollar sex industry when they moved to Sonagacchi 15 years ago.

Sonagacchi is the largest red-light district in Kolkata, having over 10,000 prostitutes in hundreds of brothels. Many of the prostitutes are teenagers sold into sexual slavery by desperate families.

"We felt that these women straight away were our neighbors," Pastor Hilton said.

In 2001, the Hiltons founded Freeset—a fair-trade business that creates organic t-shirts and burlap bags. Today, they employ over 200 women, and some men as well.

Teaching the women a trade gives them a choice beyond poverty or prostitution.

"A lot of places talk about rescuing girls," Annie Hilton told ABC. "We want them to have a choice, where they have never had one before and to provide an economic solution."

Mrs. Hilton described how prostitution is passed down from mother to daughter, and spoke of a girl who was being groomed to follow her mother's path.

"It was safer for her to work with us, but actually for me, she was the example of the future generation where the cycle can be broken," she said. "We're so proud of her."

The Hiltons' work in Kolkata threatens the livelihood of brothel owners, however, and the couple has received death threats.

"Someone rang up and said they were the police," Pastor Hilton recounted. "I don't know if they were, but threatened to kill us... if we didn't pay. They were after a lot of money and it was quite a conversation."

The couple did not pay, and has no plans to end their work. In fact, they intend to open a second factory.

"We'll do this for the rest of our lives," Pastor Hilton said.