Update 9.45: The Cranberries have issued a statement on behalf of the band, following the death of Dolores O'Riordan.
In a tweet posted at 9.23pm the band said they were devastated by the loss of the singer.
They said: "We are devastated on the passing of our friend Dolores. 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"
We are devastated on the passing of our friend Dolores. 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— The Cranberries (@The_Cranberries) January 15, 2018
Update 7pm: London's Met Police are investigating the death of Dolores O'Riordan in a hotel room in the city.
In a statement, in which they did not confirm her identity, the force said: "Police in Westminster are dealing with a sudden death.
"Officers were called at 9.05am on Monday, January 15 to a Hotel in Park Lane, W1."A woman in her mid 40s was pronounced dead at the scene.
"At this early stage the death is being treated as unexplained. Inquiries continue."
A spokeswoman for London Hilton, on Park Lane, said: "It is with deep regret that we can confirm a guest sadly passed away at the hotel on Monday 15th January.
"We offer our sincere condolences to their family at this difficult time.
"Team members acted swiftly to alert the Metropolitan Police and we are cooperating fully with their investigation.
"All further enquiries should be directed to the police."
Earlier: The family of The Cranberries singer Dolores O'Riordan are "devastated" by her death at the age of 46, her publicist has said.
The musician was in London for a recording session when she died suddenly.
A statement said: "Irish and international singer Dolores O'Riordan has died suddenly in London today.
"She was 46 years old.
"The lead singer with The Cranberries was in London for a short recording session. No further details are available at this time.
"Family members are devastated to hear the breaking news and have requested privacy at this very difficult time."
The singer, from Limerick, enjoyed success with the band in the 1990s with hit singles including Linger and Zombie.
In May 2017 The Cranberries cancelled a string of shows after O'Riordan was instructed by her doctors to stop working for a month for medical reasons associated with a back problem.
A further set of shows in North America, due to take place in September and October, were cancelled in July.
On December 20 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"
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— The Cranberries (@The_Cranberries) December 20, 2017
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 alleged air rage incident.
The singer had previously admitted three assaults and obstructing a garda after being taken off an Aer Lingus flight from New York's JFK to Ireland on November 10 2014.
Medical reports produced for the trial at Ennis District Court revealed she had been suffering from mania, mental illness and severely impaired judgment at the time of the incident, and that she remembered nothing about it.
O'Riordan was mother to son Taylor and daughters Molly and Dakota.
President of Ireland Michael D Higgins led tributes to the singer, saying: ""It is with great sadness that I have learned of the death of Dolores O'Riordan, musician, singer and songwriter.
"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 all those who follow and support Irish music, Irish musicians and the performing arts her death will be a big loss."
Irish band Kodaline also offered condolences, writing on Twitter: "Absolutely shocked to hear about the passing of Dolores O'Riordan!
"@The_Cranberries gave us our first big support when we toured with them around France years ago! Thoughts are with her family and friends."
Absolutely shocked to hear about the passing of Dolores O'Riordan! @The_Cranberries gave us our first big support when we toured with them around France years ago! Thoughts are with her family and friends— Kodaline (@Kodaline) January 15, 2018