Claire Knights, 54, from Upstreet near Canterbury, was last seen in the village on 23 August, police said.

Her silver Suzuki car has since been found parked in another village, St Nicholas At Wade, officers added.

She is believed to have walked from there to Minnis Bay, where there are reported sightings of her later that afternoon.

Ms Knights is thought to have been carrying a red or pink rucksack and was walking her brown and white spaniel, Zebulon.

But while her dog was found in Minnis Bay, Ms Knight remains absent.

Her disappearance is "now being treated as suspicious", Kent Police said.

The arrested man is from Margate.

Detective Chief Inspector Kath Way said it is "entirely out of character" for Ms Knights not to contact her family.

She added: "We are keeping an open mind as to what may have happened and still hope to find Claire safe and well."

Residents with private CCTV and drivers with dashcams are being urged to look for relevant footage.