Anita Rose, 57, left her house to take her springer spaniel Bruce for a walk at around 5am in Brantham, Suffolk, on 24 July.

The mother-of-six was found unconscious with serious head injuries near Rectory Lane at around 6.25am, and died four days later at Addenbrooke's Hospital, in Cambridge.

Suffolk Police said the 55-year-old man was arrested in Ipswich and remains in custody.

Read more:
Anita Rose: New CCTV footage released of dog walker
Anita Rose: Murder investigators cordon off two new areas of interest

Specialist officers are supporting Ms Rose's family and keeping them updated on the investigation.

Ms Rose was found unconscious by a cyclist in Brantham on a track road near the sewage works and railway line.

Officers said Ms Rose's dog, which was still with her, was not harmed.

Back in August, it was reported that a post-mortem failed to find the cause of Ms Rose's death, after which Suffolk Police said officers were continuing to investigate the case as murder.

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.