Lincolnshire Police are investigating a serious sexual assault which took place in the grounds of the Usher Gallery, off Lindum Hill.

A 20-year-old woman was attacked at 3.00am on Sunday, February 28th. The victim is white, slim, and has short, dark hair. She was wearing light-coloured denim jeans, black knee-length boots, a black top, and she was carrying a white bag.

The police have no description of the suspect.

Detective Sergeant Pete Pete Grayson, the investigating officer for Lincoln CID, is appealing for anyone with information to contact him on 0300 111 0300.

UPDATE: 04/03/10

Police have released descriptions of people they would like to speak to in relation to this incident.

The offender is described as 5ft 9-6ft, 20-30 years old with short dark hair and wearing a dark long navy blue coat with a hood. A possible witness, who was seen near the gallery at around 3.30am, is described as a man with a dark green jacket, glasses and long wavy hair.

Police are keen to trace him, as he may be able to provide them with information.

DC Adam Petty of Lincoln CID said: “The offence took place between 3am and 3.40am. We urge anyone who was in the area at that time to get in touch and help us with our investigation.” Contact Lincoln CID via 0300 111 0300.