A scuffle between animal welfare activists and security guards disrupted the start of BallArena at Hotelympia last week.
The activists were protesting against caterer Aramark's contract with Huntingdon Life Sciences, an animal testing laboratory in Cambridgeshire.
Campaigners handed out leaflets to the event's 1,500 guests, claiming that Aramark supported cruelty to animals at the laboratory by having a staff feeding contract with the company.
After a minor scuffle with security staff, the activists were escorted off the premises. Bemused guests were not sure whether the disturbance was part of the evening's entertainment, which included actors posing as paparazzi photographers and stilt walkers.
Aramark declined to comment on either the protest or its contract with Huntingdon Life Sciences.