Lady Gaga has sparked rumours she will perform a surprise set at Glastonbury.
The US singer has reportedly been spotted backstage at the music festival in Pilton, Somerset, after arriving on site on Thursday (23 June).
Danny Martindale via Getty Images
There are whispers doing the rounds that she will team up with recent collaborator Mark Ronson for a DJ set in the Shangri-La area on Saturday night.
A source told The Sun she was spotted milling around behind the Pyramid Stage, revealing: “She was clocked by a few people but she kept a low profile.
However, if she does play the set, she faces a race against time to return to the States for a rather important prior engagement.
“Mark is playing officially in the early hours of Sunday morning but they are trying to make another set work because she is due back in the States to meet the Dalai Llama on Sunday,” the festival insider added.
Rex
Lady Gaga previously played Glastonbury in 2009, when she performed on the Other Stage.
No doubt she will be supporting close friend Adele at this year's festival, with the superstar set to headline the Pyramid Stage tonight.
Friday saw the likes of Jess Glynne, Disclosure, Bastille and Foals entertain the Worthy Farm crowd, while Muse played a barnstorming headline set.
Check out all the latest Glastonbury news and pics here.
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Glastonbury 2016 Day One
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British singer Jess Glynne performs at the Glastonbury music festival at Worthy Farm, in Somerset, England, Friday, June 24, 2016. (Photo by Jonathan Short/Invision/AP) (credit:Jonathan Short/AP)
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Yannis Philippakis of Foals performing on the Pyramid Stage at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Yui Mok/PA Wire)
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Mary Chateris and Rita Ora are seen backstage at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Yui Mok/PA Wire)
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EDITORIAL USE ONLY. NO USE AFTER 60 DAYS OF ISSUE DATE Matt Bellamy of Muse performing at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Ben Birchall/PA Wire)
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Dan Smith of Bastille perfroming on the Other Stage at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Ben Birchall/PA Wire)
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Wet Weather at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Matt Crossick/Matt Crossick)
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Disclosure performing on the Other Stage during the Glastonbury Festival, at Worthy Farm in Pilton, Somerset. See PA story SHOWBIZ Glastonbury. Picture date: Friday June 24, 2016. Photo credit should read: Ben Birchall/PA Wire (credit:Yui Mok/PA Wire)
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The Crowds watching Foals on the Pyramid Stage at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Yui Mok/PA Wire)
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"Metamorphosis" at Arcadia features a light show involving a giant spider at the Glastonbury music festival at Worthy Farm, in Somerset, England, Friday, June 24, 2016. (Photo by Jonathan Short/Invision/AP) (credit:Jonathan Short/AP)
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Skepta performing live on the Pyramid Satge at the Glastonbury Festival, at Worthy Farm in Somerset. PRESS ASSOCIATION Photo. See PA story SHOWBIZ Glastonbury. Picture date: Friday June 24, 2016. Photo credit should read: Ben Birchall/PA Wire (credit:Ben Birchall/PA Archive)
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GLASTONBURY, ENGLAND - JUNE 24: A general view of the Pyramid Stage as Muse perform at Glastonbury Festival 2016 at Worthy Farm, Pilton on June 24, 2016 in Glastonbury, England. (Photo by Samir Hussein/Redferns) (credit:Samir Hussein via Getty Images)
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Yannis Philippakis of Foals performing on the Pyramid Stage at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Yui Mok/PA Wire)
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Dusty Hill, left, and Billy Gibbons from U.S rock band ZZ Top perform at the Glastonbury music festival at Worthy Farm, in Somerset, England, Friday, June 24, 2016. (Photo by Jonathan Short/Invision/AP) (credit:Jonathan Short/AP)
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ZZ Top performing on the Pyramid Stage at the Glastonbury Festival, at Worthy Farm in Somerset. PRESS ASSOCIATION Photo. See PA story SHOWBIZ Glastonbury. Picture date: Friday June 24, 2016. Photo credit should read: Yui Mok/PA Wire (credit:Yui Mok/PA Archive)
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Fans in the crowd enjoying ZZ Top on the Pyramid Stage at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Yui Mok/PA Wire)
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Hugo Taylor and Millie Mackintosh are seen backstage at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Yui Mok/PA Wire)
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British musician, Damon Albarn performs at the Glastonbury music festival at Worthy Farm, in Somerset, England, Friday, June 24, 2016. (Photo by Jonathan Short/Invision/AP) (credit:Jonathan Short/AP)
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GLASTONBURY, ENGLAND - JUNE 24: Anthony Byrne and Natalie Dormer attend day 1 of Glastonbury Festival on June 24, 2016 in Glastonbury, England. (Photo by David M. Benett/Getty Images) (credit:David M. Benett via Getty Images)
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Heloise Letissier of Christine and the Queens performing on the Other Stage at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Matt Crossick/Matt Crossick)
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Wet Weather at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Matt Crossick/Matt Crossick)
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The Lumineers performing live on The Other Stage at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Ben Birchall/PA Wire)
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GLASTONBURY, ENGLAND - JUNE 24: Douglas Booth wears Converse at Glastonbury Festival 2016 at Glastonbury Festival Site on June 24, 2016 in Glastonbury, England. (Photo by Tabatha Fireman/Getty Images for Converse) (credit:Tabatha Fireman via Getty Images)
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Blossoms performing on the Other Stage at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Matt Crossick/Matt Crossick)
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Heloise Letissier of Christine and the Queens performing on the Other Stage at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Matt Crossick/Matt Crossick)
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Festival-goers seek shelter from a heavy rain shower on day three of the Glastonbury Festival of Music and Performing Arts on Worthy Farm near the village of Pilton in Somerset, South West England on June 24, 2016. / AFP / Andy Buchanan (Photo credit should read ANDY BUCHANAN/AFP/Getty Images) (credit:ANDY BUCHANAN via Getty Images)
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A view over the Glastonbury site featuring the Pyramid stage taken from a viewing tower (credit:Richard Gray/EMPICS Entertainment)
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GLASTONBURY, ENGLAND - JUNE 24: Laura Whitmore attends Day 1 of the Glastonbury Festival 2016 at Worthy Farm, Pilton on June 24, 2016 in Glastonbury, England. (Photo by Danny Martindale/WireImage) (credit:Danny Martindale via Getty Images)
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Festival goers during a rain shower at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Yui Mok/PA Wire)
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Skepta performing on the Other Stage at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Matt Crossick/Matt Crossick)
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Jess Glynne performing on the Pyramid Stage at the Glastonbury Festival, at Worthy Farm in Somerset. PRESS ASSOCIATION Photo. See PA story SHOWBIZ Glastonbury. Picture date: Friday June 24, 2016. Photo credit should read: Yui Mok/PA Wire (credit:Yui Mok/PA Archive)
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Festivalgoers in the rain at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Ben Birchall/PA Wire)
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GLASTONBURY, ENGLAND - JUNE 24: Jo Whiley attends Glastonbury Festival 2016 at Worthy Farm, Pilton on June 24, 2016 in Glastonbury, England. (Photo by Harry Durrant/Getty Images) (credit:Harry Durrant via Getty Images)
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Damon Albarn introduces the Orchestra of Syrian Musicians, on the Pyramid Stage at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Matt Crossick/Matt Crossick)
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EDITORIAL USE ONLY. NO USE AFTER 60 DAYS OF ISSUE DATE Matt Bellamy of Muse performing at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Ben Birchall/PA Wire)
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GLASTONBURY, ENGLAND - JUNE 24: Nick Grimshaw attends day 1 of Glastonbury Festival on June 24, 2016 in Glastonbury, England. (Photo by David M. Benett/Getty Images) (credit:David M. Benett via Getty Images)
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Performers on stilts at the Glastonbury 2016 Festival on Worthy Farm in Somerset (credit:Richard Gray/EMPICS Entertainment)
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Festivalgoers enjoying Glastonbowie David Bowie tribute karaoke at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Ben Birchall/PA Wire)
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The Orchestra of Syrian Musicians performing with Damon Albarn on the Pyramid Staged at the Glastonbury Festival, at Worthy Farm in Somerset. PRESS ASSOCIATION Photo. See PA story SHOWBIZ Glastonbury. Picture date: Friday June 24, 2016. Photo credit should read: Yui Mok/PA Wire (credit:Yui Mok/PA Archive)
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GLASTONBURY, ENGLAND - JUNE 24: A general view of the Pyramid Stage as Muse perform at Glastonbury Festival 2016 at Worthy Farm, Pilton on June 24, 2016 in Glastonbury, England. (Photo by Samir Hussein/Redferns) (credit:Samir Hussein via Getty Images)
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Police officers on horseback wearing angel wings at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Ben Birchall/PA Wire)
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GLASTONBURY, ENGLAND - JUNE 24: Professor Green attends day 1 of Glastonbury Festival on June 24, 2016 in Glastonbury, England. (Photo by David M. Benett/Getty Images) (credit:David M. Benett via Getty Images)
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GLASTONBURY, UNITED KINGDOM - JUNE 24: Daisy Lowe wearing Coach attends the Glastonbury Festival at Worthy Farm, Pilton on June 24, 2016 in Glastonbury, England. (Photo by Alex B. Huckle/Getty Images) (credit:Alex B. Huckle via Getty Images)
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GLASTONBURY, ENGLAND - JUNE 24: (L-R) Matt Nicholls, Oliver Sykes and Matt Kean from Bring Me the Horizon perform on The Other Stage, Glastonbury Festival 2016 at Worthy Farm, Pilton on June 24, 2016 in Glastonbury, England. (Photo by Harry Durrant/Getty Images) (credit:Harry Durrant via Getty Images)
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GLASTONBURY, ENGLAND - JUNE 24: Yannis Philippakis of Foals performs on the Pyramid Stage Glastonbury Festival 2016 at Worthy Farm, Pilton on June 24, 2016 in Glastonbury, England. (Photo by Samir Hussein/Redferns) (credit:Samir Hussein via Getty Images)
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Members of 'The Church' perform on the Greenpeace stage on day three of the Glastonbury Festival of Music and Performing Arts on Worthy Farm near the village of Pilton in Somerset, South West England on June 24, 2016. / AFP / Andy Buchanan (Photo credit should read ANDY BUCHANAN/AFP/Getty Images) (credit:ANDY BUCHANAN via Getty Images)
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GLASTONBURY, ENGLAND - JUNE 24: Nicholas Hoult attends day 1 of Glastonbury Festival on June 24, 2016 in Glastonbury, England. (Photo by David M. Benett/Getty Images) (credit:David M. Benett via Getty Images)
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EDITORIAL USE ONLY. NO USE AFTER 60 DAYS OF ISSUE DATE Matt Bellamy of Muse performing at the Glastonbury Festival, at Worthy Farm in Somerset. (credit:Ben Birchall/PA Wire)