Thirty years after a housewife’s gruesome murder the police case file remains open – and the killer’s identity unknown.

Margaret Frame vanished on her way home from Falmer High School in Lewes Road, Brighton, where she worked as a cleaner, on October 12, 1978.

She was described as a quiet woman, who was devoted to her son, Andrew, who was nine at the time.

Her husband Peter raised the alarm after looking for her himself the next day.

Ten days later her body was found in a shallow grave in Stanmer Park, Brighton. The 36-year-old, of Saunders Hill, Coldean, had been stabbed in the back and raped. Her throat was slit from ear to ear, but no knife was ever found.

Police took about 2,500 statements and made house-to-house enquiries at more than 5,000 homes.

Ray Blackwood was a ward councillor for Stanmer at the time and chairman of governors at Falmer High School.

He said: “It was very upsetting to all the staff and everybody concerned, the governors and her colleagues.”

Councillor Pat Hawkes, who has represented the area for Brighton and Hove City Council since 1981, said she has vivid memories of the aftermath of the murder.

She said: “There was an element of fear because women were confronted with their vulnerability in their own community.”

No one was ever charged with the murder.

The murder inquiry was reviewed in 2000 but without success.

A spokeswoman for Sussex Police said: “Every unsolved case is reviewed periodically or when new evidence comes to light and this case is no exception.”