Officers are appealing for help in tracing this man in connection with a bag theft on a train from Nottingham to Matlock.
At around 6.20pm on November 5, a woman boarded a train on platform four and placed her case in the overhead luggage rack.
She had a brief conversation with a man who, when she was not looking, took her bag from the rack and left the train.
He is then believed to have boarded a separate train from Nottingham to Matlock.
Officers would like to speak to the man in this image as it is believed he may have information which could help the investigation.
Anyone with information is asked to contact British Transport Police on 0800 40 50 40 or text 61016, quoting 475 of 5/11.