The talk tugged at their heartstrings and left them unsettled and in a state of flux. They felt compelled to do something to help after hearing shocking stories of women abandoned by their families, stripped of their dignity and living without any hope.
"We were both totally hit between the eyes," says Colin.
What had particularly struck him was hearing that many young women who end up in the sex industry are from rural areas where extreme poverty is rife.
"These are farmers and they are selling their daughters as the only way to get themselves out of poverty and keep the rest of the family going. It's a terrible situation," he says.
After much soul-searching, the Andertons say they felt an overwhelming sense that God was calling them to India - and they began to work out how to make it happen.
India will throw up many new challenges for the family, the most pressing at the moment being raising money for their day-to-day costs while abroad.
As volunteers they will rely on financial help from supporters in New Zealand while they are overseas.
Colin, who studied science at university, is not a person to shy away from a challenge.
When people heard the family's sheep and beef farm on top of the Kaimai Range was to be converted to dairy, they thought he'd lost the plot - but he proved them wrong. Large covered sheds were put in that not only kept the herd warm and protected paddocks from being trodden and pasture ruined, it improved milk production.
In 2007 he was the first farmer in the Bay of Plenty to install the herd homes.
"It was a lot of money and everyone thought we were mad but we knew the farm, we knew climate, and seen where things were heading. After a bit of research it was a no-brainer."
Colin says although they were committed to joining Freeset in India, the timing of their decision in 2010 had been less than ideal for the farm and the work they had put into it.
"We had the opportunity to expand and we'd taken it. You borrow money and you have a phase over the next 10 years when you pay off the debt."
But they pressed on, putting the business on the market, and while waiting for their farm to sell, they visited India and spent time working with the New Zealand/Uganda Heifer Project in Africa.
With their farm now finally sold, and a lease on another dairy farm run its course, the couple and their two young children are packing up and preparing to leave for India.
However, they are not severing their farming ties with the Bay of Plenty. A small farm they own has been leased out for four years while they are overseas.
When they get to India the Andertons, both in their 40s, will attend a three-week induction course with Freeset to acquaint themselves with the culture and language, and find out how they can best help. It's likely they'll join other expats in a rural area.
Colin is keen to be involved and use his experience to help locals farm more efficiently.
The first priority in India for Tania, a former teacher, will be the couple's children - Georgia, 9, and Daniel, 7.
They will be homeschooled but Tania says she may teach the children of other volunteers if there's a need.
On a trip to India she was shocked to see so many young women in the sex trade - girls barely older than her daughter.
"The girls there are treated less than an animal. Once they are a prostitute they are stuck.
Freeset gives them hope they would never get any other way because they are unemployable. It breaks your heart.
"The reality of being in a position to have to sell your daughter is something that I don't think we can understand.
"Freeset gives these girls a future and they have their dignity."
If you would like to support the Andertons, contact Bethlehem Baptist Church on 07 576 2344 or missions@bethlehem.org.nz
Freeset products can be bought from liminal.org.nz and marketplacers.co.nz