Lincolnshire Police are searching for a man in his 30s wearing a tracksuit top after a woman was reportedly raped in Louth.
The attack happened close to several pubs in the Upgate/Mercer Row area of the town between 7pm and 8pm on Wednesday, December 13.
Officers have said the woman in her 30s was approached from behind in the attack.
The offender is believed to be a man in his 30s who was tall, with short light-coloured hair and stubble on his face.
He was wearing a tracksuit top which had coloured triangles on the sleeves with white borders around them.
Police are appealing for potential witnesses to come forward.
DS Scott Miller, from Lincolnshire Police’s Emerald Team, said: “We are deeply distressed for the victim of this crime and our specialist officers are supporting her every step of the way through this investigation.
“We’re working on a number of lines of enquiry to try and establish the exact circumstances involved.
“If you were in this area on this evening and witnessed a struggle or something out of the ordinary please get in touch.
“If anyone will be in the area over the festive period please be extra vigilant and report any suspicious activity.”