Ellie Goulding was overheard threatening to punch a party guest on Tuesday evening, after she was told she couldn't enter a VIP area.
Speaking to The Daily Mail's Clemmie Moodie, Ellie called an attendee of the star-studded Animal Ball a 'b****' after a run-in that left her 'so mad' at around 11pm.
The 29-year-old star was fuming following an extraordinary, explosive row with a fellow reveller at one of the most exclusive and prestigious charity events of the year.
A representative for Ellie Goulding has been contacted by MailOnline for comment.
Wearing an elephant headdress at a fundraiser ball in aid of saving endangered mammals from extinction, Ellie's trouble began when she went to perch in a cornered-off area, not realising it was already reserved.
An unknown partygoer immediately confronted her, telling her in no uncertain terms the area was for VIPs only.
Perhaps the guest had not realised that the Grammy-performing star had sung for stars including Princess Eugenie, Anna Friel, Liz Hurley and Lily Cole, earlier in the evening.
The singer proceeded to put her gin cocktail down, things quickly escalated when the woman bellowed in Ellie's face: 'Don't f***ing mess with me.'
Stunned, Ellie returned to her group of friends, which included actress Anna, and ranting for the next 20 minutes.
The slightly shell-shocked blonde later told the Mail: 'That woman is a b****, I've never met anyone as mean in my life. If she speaks to me again I will f***ing punch her! I swear I'm so mad.'
Despite the elephant mask the singer was hard to miss, wearing a stunning gold lame DHELA gown with plunging neckline.
She had donned a reindeer headdress earlier in the evening at the event at London's Victoria House,
The Animal Ball, where tickets cost £2,000 for a sit-down three course dinner, featured an exhibit of animal-themed masks designed by designers including Chloé, Missoni, Matthew Williamson, Alice Temperley and Christian Dior.
The charity's presidents, Prince Charles and the Duchess of Cornwall, also hosted a dinner at Clarence House for 22 guests.
While, earlier in the evening, Princess Eugenie and singer Ellie Goulding had hosted a table at the nearby Arts Club.
Proceeds for the ball were split between Elephant Family, Space for Giants, Lion Guardians and the Aspinall Foundation.