Police are seeking to identify a man who witnessed an alleged assault in a Civic bar on Halloween last year.

Police say the man was allegedly assaulted in the toilet of a licensed venue in the city in the early hours of October 31.

The witness is described as Caucasian in appearance with short blond hair and was wearing a black T-shirt with the word “BOSS” written in white.

Anyone who can identify the man should contact police via the Crime Stoppers ACT website or on 1800 333000. Information can be provided anonymously.