At approximately 2.10am on Sunday, 5 December, officers on duty in the area of Uxbridge Road, W12 were flagged down by members of the public.
They found a 27-year-old woman who had sustained injuries after being pushed to the ground by an unknown man outside a pub. She remains in hospital undergoing treatment for a serious leg injury.
A second woman was also knocked over by the man; she did not sustain serious injuries.
An investigation has been launched by detectives from the Central West CID, which covers Hammersmith and Fulham.
They have today, Tuesday, 14 December, released a CCTV image of a man they need to speak with.
Detective Constable Laura McDonagh said: “This was a completely random assault, in which a man – without any provocation – pushed two women to the pavement.
“The injuries suffered by one of the women will require ongoing treatment and she has been left severely impacted by them.
“Assaults on women will not be tolerated and we remain committed to identifying the man responsible.
“I would urge anyone who was in the area at the time to come forward and speak with us. Likewise, if you recognise the man in the image, please phone police.”
Information can be provided to them by calling police on 101 and giving the reference CAD 901/05Dec, or by calling Crimestoppers, anonymously, on 0800 555 111.