A 81-year-old woman was found collapsed on the roadside in Faringdon.
She was taken to the John Radcliffe hospital but later died after she was found on a grass verge alongside the A420 at Buckland yesterday.
Earlier she was seen walking from the BP service station towards Buckland crossroads at about 4.05pm.
Officers don’t know if she was hit by a vehicle, suffered a fall or became ill.
A post-mortem examination will be carried out today to determine a cause of death.
Police would also like to speak to anyone travelling towards Swindon in a grey coloured hatchback around the time of the incident, as they could hold vital information.
The woman was from the Faringdon area.
Anyone with information should call PC Ed Turner on 08458 505505 or Crimestoppers anonymously on 0800 555 111.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article