The stranger started walking with her, the woman refused to engage with him and then he grabbed her causing her to scream and call for help.

The man is described as black, in his twenties, 5ft 5, stocky build. He spoke with what is believed to be a South African accent.

At the time, two men who witnessed the incident stopped to speak to the woman and asked if everything was okay. A man on a bike also stopped to help the woman and at this point the suspect walked away.

Detective Constable Stephanie West said: “We are keen to speak to the three men who stopped to help her.

“We would also encourage anyone who may have seen or heard the incident, or was in the area in the early hours of this morning to contact us.

“Also, if you believe you know who this man could be please let the police know as any amount of information could help our investigation.”

Surrey police are urging anyone with information to contact the police on the non-emergency number 101, quoting crime reference: PR/45180014861.

If you do not wish to provide your name, you can contact Crimestoppers anonymously on 0800 555111.