The Times reported on Wednesday that a security guard stood by while three people attacked the student.
Law student and gay rights activist Glenton Matthyse described the assault as "severe" and said he and two friends tried to stop the beating.
Matthyse said campus security allowed the assailants into a student residence to hide.
University spokesperson Luthando Tyhalibongo said the matter was being investigated.
"[The university] does not condone violence or approve of action that discriminates against any person's constitutional rights."
He said staff and security broke up the fight and claimed Gayla UWC members insulted the guards.
Tyhalibongo claimed Matthyse and his friends were drunk and unruly and because of this police were unable to take statements from them.
Matthyse said he and his friends were not unruly.
"A Constable Smith from Bellville South Police Station grinned and chuckled when I tried to explain what happened … When I asked him about this he said it was a form of 'stress relief'." – Sapa