CCTV cameras captured at least a dozen drivers swerving around a woman as she lay unconscious and bleeding in a road in south-east London.
At least a dozen cars are thought to have swerved around the woman
The footage shows none of the drivers stopped after avoiding the 25-year-old woman who was face down with her head in a gutter in Cray Road, Sidcup.
It was taken by a bus camera, whose driver did stop to help her.
The woman, who had a serious head injury, was treated in a south London hospital and discharged on Wednesday.
She was unable to tell people how she suffered her injuries which happened on 20 September.
A Metropolitan Police spokeswoman said they wanted witnesses to come forward to find out how the woman was injured.
Attempts are being made to contact the woman now that she has left hospital so police can interview her, a statement from Scotland Yard said.
"Officers recovered good quality CCTV footage from a 321 bus, which clearly shows drivers swerving to avoid the woman - who was bleeding profusely from a head wound and lying unconscious next to the kerb.
"We are now issuing CCTV stills of the woman in a bid to bring forward more witnesses and information.
"We are appealing to the motorists who took evasive action to avoid a collision with the woman, and anyone else who may have seen what happened" to contact us.