A man has been arrested on suspicion of murder after the death of a dog walker nearly three months ago.
Anita Rose, 57, was found seriously injured by a member of the public in Brantham, Suffolk on 24 July and died four days later in hospital.
Detectives said a 55-year-old man had been detained in Ipswich and was being questioned.
Three other people were previously arrested and bailed in connection with the incident.
A Suffolk Police spokesperson said: “The man is currently being questioned at Martlesham police investigation centre, where he remains.
“Specialist officers are supporting Anita’s family and keeping them updated on the investigation.
“Anyone with any information that may assist with this inquiry is asked to contact the major investigation team.”
Ms Rose left her home with her dog at about 05:00 BST on 24 July and was discovered unconscious by a cyclist at 06:25 near the Anglian Water sewage works and railway line off Rectory Lane.
She was taken to Addenbrooke’s Hospital in Cambridge with serious head injuries and died four days later.
Villagers reported seeing an increased police presence in Brantham on Thursday, including a helicopter and dog units.
The charity Crimestoppers has offered a £20,000 reward for information that leads to the arrest and conviction of anybody involved in the death of Ms Rose.