Madeline Anello-Kitzmiller, 20, wore only glitter to cover her chest at the Rhythm and Vines festival in New Zealand over the new year.
Footage shows the topless woman walking through crowds with her friend, Kiri-Ann Hatfield, before a man runs up to her and appears to touch her bare breast.
He runs away but the enraged pair turn around, chase after him and throw a drink in his face before hitting him repeatedly.
“We are incredibly disappointed that an incident like this has occurred”Dan Turner
The shocking video went viral when it was posted on Facebook and now the organisers of the festival have spoken out about the incident.
Rhythm and Vines event manager Dan Turner said he and his fellow organisers are “incredibly disappointed”.
He said they "do not condone any form of harrassment".
Turner added: “We are incredibly aware of the issues that arise at music events, particularly in large crowds.
"We are incredibly disappointed that an incident like this has occurred at Rhythm and Vines, and that a select few feel that it is okay to behave in this manner.
"We want our customers to enjoy themselves, in a safe environment and be able to express themselves in a way that is in keeping with other international European festivals.”
Turner continued by adding that the festival was implementing procedures to be safer for guests next year.
He said: “We know the problem exists, but it's figuring out how to combat it in a practical, communicative way that allows our patrons to feel safe.
“The festival site includes wellness areas, chill out spaces and an Angels tent for our customers, giving them the means and pathways to report any issues.
"We have also taken steps to introduce a Patron Helpline which we will roll out next year."
Madeline spoke out this week about the incident and said she stood by her reaction.
“He grabbed my breast,” she recalled.
“I hit him. There was a lot of built up anger coming from harassment throughout the day.
“This happens everywhere, not just New Zealand.
“A human's body is their own, and nobody has a right to touch you without your consent, regardless of what they're wearing or the lack thereof.”