A woman was sexually assaulted by two men in a broad daylight attack in Hammersmith.
Police investigating the attempted rape have now released an e-fit of one of the suspects.
The victim, a 52-year-old, was attacked by two unknown men near the nature reserve in Ravenscourt Park between 3pm and 3.30pm on Friday June 16, the Metropolitan Police said.
A spokesman for the force said: "The suspects grabbed the woman and carried her to a secluded area.
"She was sexually assaulted before the suspects were disturbed and made off.
"Detectives from the Met's Child Abuse and Sexual Offences Command have launched an investigation and as part of an appeal for witnesses and information, detailed descriptions of the suspects have been given and officers are releasing an e-fit of one of the men."
The suspect is described as being tanned and of eastern European appearance, aged his late 20s or early 30s.
He was around 5ft 7in tall, of slim build with dark eyes.
He had stubble and shaggy medium/long hair, and also had a small mole on left cheek, and hairy arms.
He was wearing a white t-shirt, loose-fitting grey trousers and brown leather trainers with a lighter brown stripe.
The other man is also described as of eastern European appearance, in his late 20s or early 30s.
He was around 5ft 10in tall and of stocky build with a bald head and deep voice.
He was wearing a pale blue short-sleeved cotton shirt, dark blue jeans and white trainers.
Detective Constable Michelle Newman, of the Met's Child Abuse and Sexual Offences Command, said: "This was a terrifying attack on a vulnerable woman committed in a busy park in broad daylight, and there would undoubtedly have been other people in the park who would have seen the suspects and may not have paid them much attention at the time.
“If you were in the park on that day and the e-fit or descriptions of the men jog your memory, or if you saw anything suspicious that may assist the inquiry, we would urge you to come forward and speak to us."
Anyone with information should contact detectives via SapphireNW.WitnessAppeal@met.pnn.police.uk.
Alternatively the police can be called on 101 or Crimestoppers can be contacted on 0800 555 111 for those wanting to remain anonymous.
Keep up to date with the latest news from around the county via the free Get West London app.