The children of a woman who was found murdered in Hertfordshire 35 years ago have made a fresh appeal to find her killer.

Mother-of-three Josephine Backshall, 39, from Maldon, Essex, disappeared on October 29, 1974, after leaving her home to keep an appointment in Witham, Essex.

Her body was found three days later in a field off Bury Green Lane, near Bishop's Stortford, about 35 miles from her home. She had been strangled. Her watch had also stopped at 8:10.

Despite a massive police investigation, involving police in Hertfordshire and Essex, her killer has never been found.

Her children - Christopher, Sarah and Emma, who were just 12, ten and seven when their mother died - have made a fresh appeal for information. A statement issued by them said: "Our loving mother's life was taken away from us when we were so young and we have endured 35 years of not knowing why, or by whom, she was murdered. Not only was she denied the pleasure of seeing us grow up, we now have families of our own, of whom she would have been extremely proud."

Richard Moulder from Bedfordshire and Hertfordshire's Cold Case Review Unit said: "It is felt that during the original investigation people may have withheld information or not come forward and this could have been for very good reasons at that time.

"We hope that with the passage of time that people will feel they can now speak to use about any information, however, insignificant it may seem and help to solve the mystery surrounding Josephine's death."

Mrs Backshall had placed an advert in the local papers seeking part-time work in February 1974. As a result of the advert, she received a number of calls from a man offering work. Twice she arranged appointments with the man, but he failed to turn up.

She finally met with the man, who may have called himself Dave, in Witham, where they may have discussed photographic or modelling work.

Several months passed before Josephine received another call, around 1:15pm on the day she disappeared from someone she may have referred to as Peter and arranged to meet him at 6:30pm that evening. Her children thought she was talking to their Uncle Peter, but she said that it was a man who responded to her advert before.

Josephine never returned from the meeting, although there were several possible sightings of her that evening. Around 7:15pm, a red Ford Cortina Mk 3, believed to be hers, was seen in Collingwood Road, Witham, near the car park with the bonnet up. A woman matching her description was seen beside the car.

A passer-by asked her if needed any help, but she decline and said that someone was on their way to help her.

Police also said that it was possible that Jospehine was seen in the company of a man at the Fountain Public House in Good Easter around 10:30pm that night.

She was officially reported missing the following morning.

Mr Moulder said: "Did anyone see Josephine between October 29 and November 1? Were you the man who made the appointments with Josephine in February and never turned up? your help could prove vital to the investigation.

"Josephine's car was found broken into in the Collngwood Road car park in Witham. Was it you who broke into her car? There is no indication that there is any link between her murder and her car being broken into. We want to eliminate you from our enquiries and find out if you have any new information that could help with the investigation.

"Why was she taken almost 35 miles away to Bury Green? Did he have knowledge of the area? Did anyone see a suspicious vehicle travelling towards Bury Green?"

Anyone with any information is asked to contact police on: 0845 3300222 or Crimestoppers anonymously on: 0800 555 111.

(KMcA/BMcC)