— Update on January 31: Police have arrested a 19-year-old man in connection with this incident and he is helping with enquiries at Lincoln Police Station.
Police are trying to trace a man captured on CCTV, who may have vital information about an allegation of sexual assault which occurred in Lincoln on Saturday morning.
The man was in the area at the time of the crime which happened near the entrance to City Hall on Park Street between the hours of 1:45am and 2:00am.
He is described as white, between 5ft 6 and 5ft 10, in his early 20s with blonde hair and wearing jeans and a zip up top.
The victim is reported as white, 5ft 6 to 5ft 7 with shoulder length blonde hair and wearing dark coloured shorts and a white sleeveless top.
Authorities are urging anyone who knows this man or who has information to come forward, contacting the police on 101, quoting the incident number 33 of January 28.
Alternatively call independent charity Crimestoppers on 0800 555 111.