Fears are growing over the safety of a missing 15-year-old autistic boy who was last seen in a village shop on Monday afternoon.

Teenager Ben Thomas, from Stokenchurch, has now been missing for four days, with detectives only just today sparking a witness appeal in a bid to find him.

In the last few minutes, officers have released CCTV images of Ben in a shop in Oxford Road, Stokenchurch, where he was last seen at about 3.15pm on Monday.

Investigating officer Sgt Matthew Jones said: “We are becoming increasingly concerned for Ben’s welfare as he has been missing since Monday.

“Ben has autism and is therefore considered to be quite vulnerable.

“We believe that Ben has his bus pass so he might be travelling around the local area by bus.

“If anyone sees Ben please call police immediately via 101 or in an emergency please call 999.

“Ben, if you are reading this, please make contact with your family or police so we know you are safe and well.”

Ben is white, 5ft 4ins, slim, with blue eyes and brown hair. When he was last seen Ben was wearing a school uniform with a white shirt, tie, black trousers and a black blazer.

He was carrying a black Adidas bag with white stripes.

Ben is known to frequent Stokenchurch and Hughenden.