Police have launched a murder investigation after a man’s body was found in a river in Carlisle. The body of 26-year-old Lee McKnight was found in the River Caldew in the Blackwell Hall area, near Cummersdale, at about 5.30am on Friday. A man aged 25 and four women aged 25, 40, 46 and 47 have been arrested on suspicion of murder and remain in police custody. Cumbria police said the victim’s family have been informed and are being supported by family liaison officers. Officers are “urgently seeking” a black Nissan Navara pick-up truck with the registration DV15 TZD, asking members of the public not to approach the vehicle if sighted, but to contact police immediately. Assistant chief constable Andrew Slattery said: “We are requesting the assistance of the public as part of our murder investigation into the death of Lee McKnight. “The investigators need to hear from anyone including friends and associates of Lee who might have seen him or have information on his movements on the 23rd and 24th of July, particularly in the Fusehill Street area. “Anyone who saw anything suspicious in the Blackwell Hall area during this time should make contact with the incident room. “Anyone with information or who may have CCTV, dashcam or any other means of footage of the Nissan vehicle or Lee’s movement particularly in the Blackwell Hall area in the early hours of the 24th July, please get in touch.” Anyone with information can contact police by calling 101 and asking for the North Cumbria Crime and Safeguarding Team, quoting incident number 36 of 24 July.