A gang of men and women attacked a lady walking her dogs in the town centre, leaving her with a black eye and two of her teeth knocked out.
The 30-year-old victim was in Pevensey Road between midnight and 12.20am on January 7 when she was confronted by six people who knocked her to the ground and repeatedly punched her in the head.
A man helped her to the nearby Sussex Cars taxi office to call police.
PC Cat Maddock said, “I am very keen to speak to the man who helped the victim after she was attacked as he may have seen some of what happened.
“I would also like to speak to anyone who saw or heard any of the attack or who saw a group of men and women in the area at about the same time.”
A 20-year-old woman from Eastbourne was arrested on suspicion of assault and questioned before being released on bail until March 1 while officers carry out further inquiries.
Anyone with information should call 101 quoting serial 27 of 7/1, email firstname.lastname@example.org or call the independent charity Crimestoppers anonymously on 0800 555111.