The incident happened near the racetrack in Livingston.
Detectives have issued an e-fit image of a man they want to speak to in connection with a sexual assault on a jogger in West Lothian.
They are continuing to investigate the attack on the 32-year-old female runner in Armadale, Livingston. The incident happened at around 9pm on April 25 on a footpath near the racetrack.
The man is described as white, aged around 40, with large ears and dark or black wavy hair. He was wearing a black woollen jacket, black jeans and royal blue navy trainers.
Police urgently want to trace the man, who spoke with a Scottish accent, and have appealed to people who may recognise him to contact them as soon as possible.
Detective Superintendent Pat Campbell from Lothian and Scottish Borders CID said: “Following new information, we are now in a position to release an e-fit image of a male that we wish to trace in connection with our investigations into the serious sexual assault of a woman near to Armadale on the evening of Tuesday, April 25.
“I am appealing to the communities of West Lothian and the public in general for suggestions as to the identity of the man shown in the image as a matter of urgency. Whilst we understand that this crime has caused a great deal of concern amongst the local community, I would like to reassure everyone that our officers are doing absolutely everything they can to investigate this crime.
“I would also like to advise the public to take care when walking at night in the Livingston area and to report any suspicious behaviour that they may have noticed. We are completely focussed on solving this crime and I cannot stress enough the importance of members of the public coming forward with any information that could potentially assist with our inquiries.
“If you were in the surrounding area on the evening of Tuesday 25th April, please cast your mind back and think about whether you may have seen a man of the above description or anything out of the ordinary. If you have any information at all, no matter how significant you think it might be, let us determine that as it could prove vital to our investigation.”