Officers say the woman, in her thirties, left a pub in Oxford Road at around 1.30am. She met up with a man she had met in the pub and as the two walked by an area behind the Costcutter shop in Wantage Road, the man sexually assaulted the woman.

Officers are keen to trace a large brown handbag which was being carried by the woman, as it cannot be located. The bag contained two phones, wallet, cards and other items.

DCI Linda York said: “We are in the early stages of this investigation and are doing everything to work out the circumstances of what happened and locate the offender.

“The victim had in her possession a large brown handbag which now cannot be located, so we are keen to track down its whereabouts.

“If you’ve found a bag matching this description or have information which you feel will help this investigation, please call us.

“Incidents like this are extremely rare in the Thames Valley area, but if anyone has any concerns, please contact your local neighbourhood team.”

Anyone with information on the missing bag is asked to contact Det Con Karen Brown from Reading Force CID on 101.