A woman motorist was raped after she left her car to investigate an empty child's car seat in a layby.
Detectives are hunting the suspect who sexually assaulted the victim on the A4 in Thatcham, Berkshire, at around midnight on Monday.
The driver had stopped at the location opposite the junction with Cox’s Lane after becoming concerned a child was at risk when she saw the car seat.
Thames Valley Police said they are working to understand the significance of the seat and if it’s linked to the offence.
Investigating officer Detective Inspector Alice Broad, said: “Due to the victim’s account, we are now in a position to provide further information to the public.
“We can confirm that we believe the offender was not known to the victim.
“The victim was driving on the A4 before the offence occurred. She stopped her vehicle at the scene because she saw a child’s car seat in a layby and was concerned there might be a child at risk because the car seat was empty.
“Thames Valley Police is working to understand the significance of the child’s car seat and whether it is linked to the offence."
Det Insp Broad added: “We are appealing to anyone with footage or information to please come forward.
“No matter how insignificant you think your information might be, please provide it to the police or anonymously to Crimestoppers.
“We would like to hear from anyone with footage, whether dashcam, mobile phone or CCTV, from the A4 in Thatcham between about 11pm Sunday 15th until about 12.15am on Monday the 16th August.”
More police officers had been deployed to the area in response to the incident.
Det Insp Broad said: This is a concerning incident and one that has understandably caused anxiety in the local community.
"However, such offences are extremely rare and a thorough investigation is underway to identify the offender."
Police advised people if they see something that concerns them when driving, make a note of the location and call authorities so they can make checks.