A convicted rapist and murderer who is believed to have killed teenager Elsie Frost in 1965 was identified as a "likely suspect" just days after her murder, an inquest has heard.
The inquest at Wakefield Coroner's Court heard that a file on Peter Pickering who was dubbed the "Beast of Wombwell" - was sent to West Yorkshire from Scotland Yard but was returned as the force could not trace him.
Two months later, another man was charged with the 14-year-old's murder but was eventually cleared - leaving the case uninvestigated for nearly 50 years, the inquest was told.
The new inquest into Elsie's death is being held after her brother and sister, Colin Frost and Anne Cleave, successfully campaigned for a fresh review and comes after West Yorkshire Police revealed that Pickering was close to being charged with Elsie's murder at the time of his death in March last year.
Mrs Cleave spoke of her anger that the case had been left "in limbo" following the exoneration of Ian Spencer in March 1966 - leaving Pickering free to go on to murder 14-year-old Shirley Boldy and kidnap and rape an 18-year-old woman in Barnsley in 1972.
The inquest heard that police in Wakefield were sent a file on Pickering from the Metropolitan Police on October 13 1965 - just four days after Elsie was stabbed to death as she walked back from a sailing club event.
On October 25, the force returned the file with a note, which read:
The force requested that the Metropolitan Police informed them if Pickering was apprehended. The inquest heard that a coroner at the original inquest, in December 1965, formally accused railway fireman Mr Spencer of murdering Elsie.
Mr Spencer was held in custody until a court hearing in March 1966 in which a High Court judge directed the jury to find him not guilty.
The High Court quashed the decision by the original inquest earlier this year.
Lee Spencer, Mr Spencer's son, told the inquest that, despite being formally acquitted of Elsie's murder, his father was repeatedly questioned by police in relation to other crimes.
He also described how his father would make detailed notes following his arrest so he could account for his movements.
Mr Frost, who was five when his sister was murdered, told the inquest that his sister's death had "split the family wide open" and left his parents feeling guilty.
Mr Frost agreed with coroner Kevin McLoughlin that Elsie's murder had a "truly devastating impact" on the family and said the fact that no-one had been convicted added to the distress.
Mr McLoughlin told the inquest that Elsie was described in statements as a "model child" who was expected to become head girl at school. Mr Frost added that his older sister was like a mother to him and described how she taught him to tie his shoelaces.
He said: "She carried out that role, in my eyes, perfectly."