Officers are seeking the public's help in establishing Christopher's whereabouts after he was reported missing from his home in Hebden Bridge on Thursday, May 25.
Police are also re-releasing CCTV images from the day the 26-year-old went missing in the hope that someone will recognise him and get in touch.
Detective Inspector Dave Shaw, of Calderdale CID, said: "I am urgently appealing to anyone who believes they may have seen Christopher or knows his whereabouts to contact the police as soon as possible.
"It has been nearly two weeks since Christopher was last seen and his friends and family are extremely worried for his welfare."
Christopher is described as white, 5ft 6in, with short mousy brown hair and a short brown beard. He was last seen wearing black trainers, grey tracksuit bottoms and a grey hoody with red writing across the chest.
Det Insp Shaw said: "Our investigation remains ongoing and we have officers conducting extensive enquiries to locate him.
"It is believed that Christopher does have links to Rochdale and Burnley areas and he has previously travelled there."
Anyone with any information is asked to contact Calderdale CID immediately via 101, quoting log number *702 of 25/05.