DETECTIVES have released CCTV footage of a man they believe may be able to help solve the mystery surrounding a man found with serious injuries in Birkenhead.

Emergency services were called at around 9.20am on Thursday, December 27 following reports that a man, in his 40s, was found unconscious in Victoria Fields.

He was taken to hospital by an ambulance with a head injury and he remains in a serious but stable condition.

The man is black, 5ft 8in, of medium build with short black hair and brown eyes.

CCTV footage has revealed that a man walking a white dog passed the man before the incident - there is no suggestion that he has done anything to have hurt the victim and police say he could have vital information about the incident.

Detective sergeant Clint Wilkinson said: "Our enquiries are continuing to establish how the man came to sustain his injuries.

“We believe that he left his home address in Victoria Fields around 6am to go to a local shop but never arrived.

"At some point during that journey we believe a man walking a white dog was passed by the man, who may have been running.

“Are you the dog walker seen in this footage?

"If so, did you see a man matching his description in the area that morning, or anything suspicious?

"At this stage we are keeping an open mind as to what happened, but are asking for anyone who saw anything that morning, or has heard any information locally since, to come forward.

"You may have home CCTV and have seen him passing, so please check as your information could be vital."

Anyone with information is asked to contact Merseyside Police on social media via @MerPolCC, call 101 with reference 18400078242 or Crimestoppers anonymously on 0800 555 111.