Police are searching for a specific witness who spoke to a woman before she was reported missing - days before her body was discovered in the River Thames in Marlow. 

The death of 55-year-old Ruth Smith, who was a teacher living in Windsor, is being treated as unexplained but not suspicious. 

On April 25, at around 3.30pm, Thames Valley Police received reports that a woman had entered the water and then re-emerged from the water at the end of St Peter's Street, Marlow, near to the jetty entrance of the River Thames and the Two Brewers pub. 

During this time it is believed that she might have spoken to a man, before she then again disappeared.

Her body was pulled from the river on May 7. 

Police are now carrying out an investigation on behalf of the coroner to find the man who may have spoken to Ruth. 

He is described as a man in his mid-to-late fifties, short brown/greying hair which was receding on top, 5ft 6ins to 5ft 8ins tall of average build, wearing light coloured trousers, a casual shirt and a beige Harrington/windcheater jacket.

Investigating officer, Detective Sergeant Stephen Fox, of Force CID based at High Wycombe, said: "We are carrying out an investigation on behalf of the coroner into this unexplained but non-suspicious death. 

"We are appealing for this potential witness to come forward, as he may have been the last person to see Ruth before she went missing."