A man was found unconscious and seriously injured outside a nightclub in Sunderland.
Officers were flagged down by a concerned member of the public who found the injured man outside the venue in the Holmeside area of Sunderland city centre on Friday.
The 27-year-old male was taken to hospital by ambulance where he remains in a critical condition.
An investigation was launched into the incident and officers are appealing for anyone who was in the area and may have information to come forward.
Chief Inspector Paul Woods said: “It’s unclear exactly how the 27-year-old sustained his injuries but they are so extensive that it is vital we get to the bottom of the circumstances surrounding how he was found severely injured in a city centre street.
“The injured man underwent emergency surgery and is unable to assist police at this time.
“So it is of extreme importance that anyone who witnessed the incident or has any information gets in touch.
“We are also appealing for dashcam footage taken in the area and CCTV footage also.”
Any witnesses or anyone with footage is asked to contact police on 101 quoting reference 1145 100720 or independent charity Crimestoppers anonymously on 0800 555 111.
