Sinead O’Connor was found unresponsive at her home in London and pronounced dead at the scene.
Her next of kin have been notified, and her death is not being treated as suspicious.
A file is now going to be prepared for the coroner.
Read more: An unapologetic singer’s rise to stardom
In a statement, the Metropolitan Police said: “Police were called at 11.18am on Wednesday 26 July to reports of an unresponsive woman at a residential address in the SE24 area.
“Officers attended. A 56-year-old woman was pronounced dead at the scene.”
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O’Connor was best known for her 1990 song Nothing Compares 2 U – the track made her a global star, partly due to its iconic video.
‘Beyond compare’: Tributes paid to Sinead O’Connor after singer’s death
Sinead O’Connor dies: The unapologetic singer’s rise to stardom and personal struggles
Sinead O’Connor: Irish singer dies aged 56 as family ‘devastated’
Yesterday, her family said they were “devastated” by the death of “our beloved Sinead”.
Two weeks ago, O’Connor had told her fans that she had recently moved back to London after a 23-year absence – and she was “very happy to be home”.
She said she was finishing an album that was going to be released early next year – and planned to launch a world tour spanning Australia, New Zealand, Europe and the US.
Morrissey pays tribute – and attacks music industry
On his website, former Smiths frontman Morrissey paid tribute to O’Connor – and alleged that she had been mistreated by the music industry.
“There is a certain music industry hatred for singers who don’t ‘fit in’,” he claimed.
Morrissey praised her “proud vulnerability” – describing O’Connor as someone who refused to be labelled and “had the courage to speak when everyone else stayed safely silent”.
O’Connor had a troubled childhood and spoke openly about her mental health issues.
When her teenage son Shane took his own life in 2022, she tweeted to say there was “no point living without him”, and spent time in hospital.
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The mother of four was also a critic of the Catholic Church well before allegations of sexual abuse were widely reported – and made headlines by ripping up a photograph of Pope John Paul II while appearing as a guest on Saturday Night Live.
Irish President Michael D Higgins said: “One couldn’t but always be struck by the depth of her fearless commitment to the important issues which she brought to public attention, no matter how uncomfortable those truths may have been.”
She converted to Islam in 2018 and adopted the name Shuhada Sadaqat, but continued to use Sinead O’Connor professionally.
Yusuf Islam, the musician formerly known as Cat Stevens, said: “Sad to hear of the passing of sister Shuhada Sadaqat, also known as Sinead O’Connor. She was a tender soul, may God, Most Merciful, grant her everlasting peace.”
Fellow musician Tori Amos described O’Connor as a “force of nature” – and a songwriter whose talent we will not see the likes of again.
“Such passion, such intense presence and a beautiful soul, who battled her own personal demons courageously. Be at peace dear Sinead, you will forever be in our hearts,” she wrote.
In her 2021 memoir Rememberings, O’Connor had written: “Everyone wants a pop star, see? But I am a protest singer. I just had stuff to get off my chest. I had no desire for fame.”