An image on the branch’s Facebook page showed a guest sporting a black curly wig, black painted face, large white painted lips and white circles around their eyes as part of the event last weekend.
Hundreds of people commented on the now-deleted photo, denouncing the guest’s costume, calling it racist and insensitive.
In a statement on its Facebook page, the branch apologised, saying the costume was worn in innocence and the spirit of the night.
“We did not pick up that it had the potential to offend. We apologise unreservedly for any offence that has been caused.
“We strive to be a welcoming and inclusive part of our community, and are incredibly sorry that we have fallen short on this occasion.”
“We are aware that some people have downloaded [the photo] and are sharing it further than our reach extends and we respectfully ask that all copies are destroyed.”
Last week, a spokesperson for the national body governing the Returned Services Association apologised, saying the incident was “incredibly disappointing” and it prided itself on “being a warm and welcoming place in the community”.