Claudia Elizabeth Lawrence, 35, was last seen on Wednesday afternoon by work colleagues at the University of York.

She left work at her usual time, around 2.15pm, and has not been seen since.

Detective Chief Inspector Lucy Pope, who is leading the investigation, said: “We are becoming increasingly concerned for Claudia’s safety as it is completely out of character for her to be missing for so long.

“Claudia’s family are becoming increasingly distressed at her disappearance and we are aanxious to put an end to their anguish.

“We appeal to anyone who has seen Claudia, spoken to her or knows of her whereabouts to contact police urgently.

“Or better still, if Claudia hears or reads this appeal, please get in touch with friends, family or police and let us know that you are safe.”

Claudia is described as white, around 5ft 6in tall, slim with brown hair and brown eyes.

She was last seen wearing a white t-shirt, blue jeans and trainers.

Anyone with any information is asked to phone North Yorkshire Police on 0845 60 60 247.