A man picured in CCTV images released by police following a sexual assault in Lancaster has now been identified by detectives.
A 37-year-old man is now helping police with their inquiries, officers say.
An investigation is ongoing into the attack, on a 19-year-old woman, in the early hours of Saturday, December 10.
The woman was assaulted by a man at around 2.45am on Milking Stile Lane before a member of the public intervened, forcing the attacker to flee.
The ‘good Samaritan’ came forward and spoke to police following an earlier appeal.
The offender is described as black, of medium build and with short dark hair. He was wearing dark trousers and either a dark waistcoat over a long sleeved shirt or a two tone coloured top.
DI Phil Jones, of Lancaster CID, said: “I would like to take this opportunity to thank members of the public who have assisted so far and the good Samaritan who came forward following our earlier appeal.
“They have provided vital information and I have no doubt that the actions of the good Samaritan prevented a more serious attack on the victim, who continues to be supported by specially trained officers after this traumatic incident.”
Anyone with information should contact police on 101 quoting log number 0225 of December 10 or independent charity Crimestoppers on 0800 555 111 or online at crimestoppers-uk.org.