A witness who might have important information about the tragic death of maths teacher Ruth Smith is being asked to come forward by police.

Mrs Smith, 55, a mother of two who lived in St Mark's Road, Windsor taught at St Edwards Ecunemical Middle School in Parsonage Lane.

She was last seen near St Peter’s Street, Marlow on Wednesday, April 25.

On Monday, May 7 her body was discovered in the Thames in Bisham Lane, Marlow.

Now police believe Mrs Smith may have spoken to a man just before she disappeared.

At around 3.30pm on Wednesday, April 25 police received reports that a woman had gone into the water, reemerging at the end of St Peter's Street, Marlow near the jetty entrance of the Thames and the Two Brewers pub.

It was after this report that police launched a missing person investigation.

They are now investigating on behalf of Berkshire's coroner and would like to hear from the man who may have spoken to Mrs Smith before she disappeared for a fatal second time.

He is described as a man in his mid-to-late fifties with 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."

If you have any information relating to this case, please call 101 quoting reference '43180124579', or contact Crimestoppers anonymously on 0800 555 111.