The lead singer of Irish rock band The Cranberries has died suddenly aged 46.
Dolores O'Riordan had been in London for a recording session at the time of her death on Monday, according to her publicist.
Metropolitan Police said O'Riordan was pronounced dead at the Hilton on Park Lane, adding: "At this early stage the death is being treated as unexplained."
O'Riordan's family are said to be "devastated" and have asked for privacy.
The Cranberries tweeted: "She was an extraordinary talent and we feel very privileged to have been part of her life from 1989 when we started the Cranberries.
"The world has lost a true artist today. Noel, Mike and Fergal."
O'Riordan's producer, Youth, whose real name is Martin Glover, posted a picture of the singer on Instagram and said he had been waiting in the studio for her when he heard the news.
He wrote: "Tragic and awful news as we were waiting for her in the studio today...thoughts are with her family and loved ones."
Irish President Michael D Higgins was among those who paid tribute to the singer, saying: "Dolores O'Riordan and The Cranberries had an immense influence on rock and pop music in Ireland and internationally.
"I recall with fondness the late Limerick TD Jim Kemmy's introduction of her and The Cranberries to me, and the pride he and so many others took in their successes.
"To her family and all those who follow and support Irish music, Irish musicians and the performing arts her death will be a big loss."
On 20 December, O'Riordan tweeted from the band's official account, writing: "Hi All, Dolores here. Feeling good! I did my first bit of gigging in months at the weekend, performed a few songs at the Billboard annual staff holiday party in New York with the house band.
"Really enjoyed it! Happy Christmas to all our fans!! Xo"
Her last post on Twitter, on 3 January, said she was travelling to Ireland.
The band, which was formed in 1989, rose to international fame in the 1990s and sold more than 40m records worldwide, with hits including Zombie, Linger and Dreams.
The group released five albums before taking a break in 2003.
O'Riordan, from Friarstown, Co Limerick, released two solo albums during the hiatus before the band reformed in 2009.
In May 2017, The Cranberries cancelled a number of shows after doctors told O'Riordan to stop working for a month for medical reasons linked to a back problem.
Another set of shows in North America, due to take place in September and October, were cancelled in July.
In February 2016, O'Riordan said she would use "music, dancing and performing to improve her mental health" after avoiding a criminal conviction for assault at an airport.
She was ordered to pay €6,000 to charity for headbutting, kicking, hitting and spitting on police officers following an air rage incident.
The singer had previously admitted three assaults and obstructing an officer after being taken off an Aer Lingus flight from New York's JFK to Ireland on 10 November 2014.
Medical reports produced for the trial revealed she had been suffering from mental illness and severely impaired judgement at the time of the incident, and that she remembered nothing about it.
O'Riordan is survived by her three children; son Taylor and daughters Molly and Dakota.
The 46-year-old split from her husband of 20 years, former Duran Duran tour manager Don Burton, in 2014.
"We are crushed to hear the news about the passing of Dolores O'Riordan," Duran Duran said on Twitter.
Irish singer Ronan Keating said he was "totally shocked" about the death of O'Riordan, who he described as an "incredible talent and a lovely soul".