A 30-year-old woman has been raped while walking along a footpath in Livingston.
Police said the woman was approached from behind by a man in Riverside Court at 5.45pm on Wednesday.
The suspect is described as white, aged in his late 20s, around 5ft 9in and of slim build.
He was wearing a black hoodie with the hood up, and a black shiny puffer-style body warmer.
He ran off in an eastward direction following the attack.
Police are appealing for a male cyclist who may have been in the area at the time to contact them.
Detective Inspector Craig Higgins said: “This was a terrifying ordeal for the victim and we are doing everything we can to provide her with all the necessary support she requires at this time.
“Officers have been searching the Riverside Court area, checking CCTV and carrying out inquiries in the surrounding area since this was reported.
“I am appealing to anyone who was in the area at the time who may have seen anything suspicious or a man matching this description to come forward.
“We believe there was a male cyclist who passed by shortly after the attack and may have seen the suspect running off.
“He is described as in his late 30s or early 40s, with brown hair and a beard and was using a blue bike.
“If you were cycling in the area at the time, please think back and get in touch with police if you have any information that may be able to assist our investigation.
“It does not matter if you think your information is small or minor – it could be just the detail we are looking for to help build a bigger picture of the circumstances.
“I would like to reassure the local community that we are doing everything we can to identify the man responsible. A highly visible police presence is in place in the area and that will remain while our investigation continues.”
Anyone with information is asked to contact police on 101, quoting reference number 2802 of September 30.