A man has been arrested on suspicion of the murder of a woman found unconscious after taking her dog for a walk in Suffolk. Anita Rose, 57, left her house to take her springer spaniel for a walk at about 5am on 24 July. She was found at about 6.25am lying on a track road near a sewage works and railway line in Brantham by a cyclist, who called an ambulance. With her jacket taken, she was found wearing only a bra on her upper body, and leggings and trainers on her lower half, with the dog’s lead wrapped around her leg, Suffolk constabulary said. Rose was taken to hospital and died four days later. The dog was not harmed. Police arrested the 55-year-old suspect on Monday morning, the force said. The man was being questioned at Martlesham police investigation centre, it said. There had been three previous arrests in connection with the inquiry – of a man in his 20s and a 45-year-old man on suspicion of murder, and a 37-year-old woman on suspicion of handling stolen goods. All three were released on bail. Last month, Suffolk police released CCTV images of two potential witnesses that officers wanted to speak to. They stressed that the pair were not suspects in the case but that officers believed they might be able to assist with inquiries. One of them had now been identified and was assisting officers, the force said. Police are continuing to try to identify the second person. The independent charity Crimestoppers has offered a £20,000 reward for information that leads to the arrest and conviction of anybody involved in the death of Rose. Anyone with any information that may assist with the inquiry is asked to contact the major investigation team via the online portal. Alternatively, they can contact Crimestoppers on 0800 555 111 or online at www.crimestoppers-uk.org.