Detectives are appealing for information after a woman was sexually assaulted in Acton.
Police were called at approximately 01:45hrs on Monday, 19 July following a report that a woman in her 40s had been sexually assaulted in Twyford Abbey Road.
She was reportedly approached by an unknown man who grabbed her by the throat before sexually assaulting her. Officers are providing support to the victim.
The suspect has been described as being dressed in dark clothing and is believed to be aged between 20 and 25.
Detective Constable Christine Denney, from the West Area Public Protection Team, said: "I am appealing for anyone who was in the area and who saw this incident, or witnessed a man fleeing the scene, to contact us immediately.
"Any information you have could prove vital in helping us identifying and apprehending this person."
Anyone with information is asked to call police on 101 or tweet @MetCC and quote Cad 632/19Jul.
Alternatively, you can call the independent charity Crimestoppers anonymously on 0800 555 111.
There have been no arrests; enquiries continue.