Duffy shared what happened to her during the month-long ordeal, where she was drugged in her own home.
"It was my birthday, I was drugged at a restaurant, I was drugged then for four weeks and travelled to a foreign country," the singer wrote in a post published on her website.
"I can't remember getting on the plane and came around in the back of a travelling vehicle. I was put into a hotel room and the perpetrator returned and raped me."
Her heartbreaking account includes the singer saying she feared for her life and that she contemplated running away from the man who kidnapped her.
"I was afraid he would call the police on me, for running away, and maybe they would track me down as a missing person.
"I do not know how I had the strength to endure those days, I did feel the presence of something that would track me down as a missing person.
"I flew back with him, I stayed calm and as normal as someone could in a situation like that, and when I got home, I sat dazed, like a zombie. I knew my life was in immediate danger, he made veiled confessions of wanting to kill me."
She does not name the attacker in her account. The singer says the event "destabilised" her severely.
"In the aftermath, I would not see someone, a physical soul, for sometimes weeks and weeks at a time, remaining alone."
Duffy wrote she decided to share details of her trauma to rid herself of the shame she felt.
"I believe that if you speak from the heart within you, the heart within others will answer. As dark as my story is, I do speak from my heart, for my life, and the life of others, whom have suffered the same.
"I have no shame in telling you either I had spent almost 10 years completely alone and it still burns my heart to write it," she wrote.
"I owe it to myself to say it, I feel obliged to explain how challenging recovering truly was and to finally disclose it. I hope it comforts you to feel less ashamed if you feel alone."
Where to get help:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youth services: (06) 3555 906
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• CASPER Suicide Prevention
If it is an emergency and you feel like you or someone else is at risk, call 111.
If you're in danger now:
• Phone the police on 111 or ask neighbours or friends to ring for you.
• Run outside and head for where there are other people.
• Scream for help so that your neighbours can hear you.
• Take the children with you.
• Don't stop to get anything else.
• If you are being abused, remember it's not your fault. Violence is never okay.
Where to go for help or more information:
• Women's Refuge: Free national crisis line operates 24/7 - 0800 refuge or 0800 733 843 www.womensrefuge.org.nz
• Shine, free national helpline 9am-11pm every day - 0508 744 633 www.2shine.org.nz
• It's Not Ok: Information line 0800 456 450 www.areyouok.org.nz
• Shakti: Providing specialist cultural services for African, Asian and Middle Eastern women and their children. Crisis line 24/7 0800 742 584
• Ministry of Justice: www.justice.govt.nz/family-justice/domestic-violence
• National Network of Stopping Violence: www.nnsvs.org.nz
• White Ribbon: Aiming to eliminate men's violence towards women, focusing this year on sexual violence and the issue of consent. http://www.whiteribbon.org.nz