A woman has been arrested on suspicion of murder after a man was found stabbed to death in the street in Liverpool. The woman, 25, was treated for knife wounds in hospital before being taken into police custody on Tuesday morning. Merseyside police said the 39-year-old man, from Knotty Ash in Liverpool, had sustained fatal stab wounds when he was discovered in the Old Swan area of the city at about 8.55pm on Monday. Detectives said the investigation was still in the early stages and that they were keeping an open mind about the circumstances of the incident. Earlier, Merseyside police said they were called to reports of a man with “significant injuries” in the Old Swan area. Officers administered CPR but the man was pronounced dead at the scene. Police then found a woman with stab injuries inside a house on Rock Grove, where the man had been found in the street. Ch Insp Jim Wilde said: “This was a tragic incident in which a man has sadly lost his life. An investigation is now under way, which is in the very early stages as we seek to establish what has happened. “I would appeal to anyone who was in the area of Rock Grove this evening between 8.30pm and 9pm to please get in touch. You may have seen or heard something suspicious which has led to this tragic incident. “It is vital that people with information, no matter how small, to please contact us as it might be vital to the investigation.” Rock Grove residents expressed their shock as the street and surrounding areas were closed for crime scene investigation work on Tuesday. CCTV and house-to-house inquiries were being conducted in the area. Merseyside police urged anyone with information to privately message @MerPolCC on Twitter, or call 101, quoting log 1068 of 14 March. Members of the public can also contact Crimestoppers anonymously on 0800 555 111 or online.