Floodlight is a platform dedicated to raising awareness of modern slavery - something which Emma has passionately campaigned for throughout her career as patron for human rights charity, the Helen Bamber Foundation.
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The Hollywood actress made the revelation on Wednesday's show, telling Princess Eugenie: "One of the most shocking things that I ever, ever experienced when I was invertsigating trafficking...was that the massage parlour around the corner from my house was one of the places where my friend had been held prisoner and was serially raped, in this massage parlour, round the corner from my house.
"That was an extraordinary thing to find out.
Tindy was adopted by Emma and her husband Greg Wise
"The more people that know these stories the more people will see and the more people we will be able to protect."
Throughout the conversation with Eugenie and podcast partner Julia de Boinville, the 63-year-old revealed it was thanks to her work with human rights organisations which led her to find her son Tindy, whom she adopted in 2004.
Emma explained: "I met Tindy through another organisation that I support and work with called the refugee council and he was as you know kidnapped as a child and forced into the militia in Rwanda.
"He got to the UK after horrible experiences when he was just 16. So I met him when he was 16, and actually, he came to ours for his 17th birthday, which is December, at this party for the Refugee Council and it was one of those strange… I do think as humans are very mysterious we make this connection with one another if we're lucky enough to meet people from very very different places.
Princess Eugenie's first podcast aired on April 27
"We often find that there are deep connections and bonds between us and that they're not necessarily created by shared culture and shared visions…shared anything. You can come from a completely different background and be terribly similar.
"Tindy and I had one such connection which slowly grew into a mother-son relationship which is, with my daughter, the most precious things in my life and he understands obviously the processes of kidnap and abduction very very well and was very close to Helen Bamber as well.
"He enormously helpful to some of the refugees who ended up at that foundation so he's always been very much a part of it and we've travelled together and learnt a lot about life in places like Myanmar and Liberia so we've done work on all sorts of areas of human experience together and that's been fantastic to share that with him."
The mother-of-two also discussed her daughter Gaia and explained: "She doesn't work for Greenpeace… I wish she would actually!
"She wants to act and what can you do! Whatever makes her happy but she will also be very active all her life because she's always been surrounded by people who have been talking about what we like to call issues. But just about the reality of human life and one of the realities is climate change and one of the realities is trafficking and one of the realities is child soldiering you know as well as bake off, these things exist side by side."
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