At about 11.30pm on Wednesday December 30 the victim had been on a night out on King Street and as she left a club, she was approached by a man.
He asked her age and she told him she was 16 and agreed to walk with him. Minutes later he raped her in an alleyway.
The man is described as white, about 50-years-old, plump and was wearing blue jeans and a brown jumper, with navy jacket and brown shoes.
Police have today (Friday) released CCTV of a man they want to speak to in connection with the attack.
PC Ann-Marie Greenall of the Child Sexual Exploitation Team on the Wigan division said: “This was a horrific incident where a vulnerable young girl who was targeted by a much older man and raped.
“This was a very distressing attack and we understand that people will be concerned. We would like to assure people that we are doing everything we can to find the attacker.
“Anyone who recognises the man or has any information that could help police with this investigation is asked to get in touch. Any information, no matter how small could be vital to this investigation.”
Anyone with information is asked to call police on 0161 856 1835, 101 or the independent charity Crimestoppers, anonymously, on 0800 555 111.