Aimee Duffy, the Welsh pop singer known as Duffy who retreated from the public eye following her hugely successful debut album Rockferry, has said she was drugged, held captive and raped by an unidentified person.

In a statement on her official Instagram account she said: “The truth is, and please trust me I am OK and safe now, I was raped and drugged and held captive over some days. Of course I survived. The recovery took time. There’s no light way to say it. But I can tell you in the last decade, the thousands and thousands of days I committed to wanting to feel the sunshine in my heart again, the sun does now shine.”

She does not detail when the attack happened, but said she came to the decision to reveal the attack after a journalist had contacted her: “He was kind and it felt so amazing to finally speak … In the following weeks I will be posting a spoken interview. If you have any questions I would like to answer them, in the spoken interview, if I can.”

Duffy, 35, adds: “You wonder why I did not choose to use my voice to express my pain? I did not want to show the world the sadness in my eyes. I asked myself, how can I sing from the heart if it is broken? And slowly it unbroke.” She pleaded for support, and for no intrusion into her family life.

With a vintage pop sound that matched contemporaries like Amy Winehouse and Adele, Duffy’s 2008 debut album Rockferry was sensationally successful. Powered by the chart-topping single Mercy and the ballad Warwick Avenue which peaked at No 3, it became the UK’s biggest selling album that year, and won her three Brit awards. It eventually sold over 9m copies worldwide, and was a hit in the US, reaching the top five and winning a Grammy.

She released a less successful follow-up, Endlessly, in 2010. She has only released one song since then, Whole Lot of Love, which featured on the soundtrack to 2015 Tom Hardy gangster film Legend. She appeared in the film as nightclub singer Timi Yuro.

In 2013, she told Esquire magazine: “I took a step back. I thought: I’m going to slow all this right down … It all got so complex, such responsibility. I was serenading people to sleep, not running Nasa. Suddenly I was a product, an enterprise, a businesswoman. But mostly I wanted to be human.”

In 2014, her producer Bernard Butler said: “She went off the rails and it all went pear-shaped for her … But I always had quite a lot of sympathy for her, because she was young, from this tiny village in Wales, and she was just hurled into the fire.”

In a 2011 interview with Marie Claire she noted how her musical heroes were victims of tragedy. “Where I want to be and where I think I’ll be [in 20 years] are very different things. The way history would have it is that I would end up in some form of tragic event. The people that I’ve loved – Dusty, Marvin, Edith Piaf – they didn’t always have happy stories. That’s the way history would have it … I take every day as it comes. You’re at the mercy of life.”