Detectives investigating the murder of schoolgirl Elsie Frost are considering 100 new lines of enquiry.
Police have received 40 calls since the launch of a major reinvestigation into the case, fifty years after the 14-year-old was stabbed to death on October 9, 1965.
It is thought Elsie had been walking home along the Calder and Hebble Canal after an afternoon watching friends sail at Horbury Lagoon.
Police believe she left the lagoon, at around 3.50pm.
While entering a railway tunnel just off the canal towpath, which now leads onto Monckton Road, she was attacked from behind and stabbed in the back and twice in the head.
Her body was found by a dog walker, by the ABC steps at around 4.15pm.
A post-mortem confirmed she died of shock and blood loss.
And new witness reports now refer to a man in his early 20s seen near to the ABC steps around the time Elsie’s body was discovered.
He was slim to medium build, had dark hair and was wearing a duffel coat.
The Homicide and Major Enquiry Team (HMET) have issued a picture of an officer wearing a similar style coat.
Detective Chief Inspector Elizabeth Belton is leading the investigation.
She said: “We received a highly encouraging response to our new appeal last October and have since been progressing lines of enquiry to try and find Elsie’s killer.
“Clearly, it is significant that after such a long passage of time, we have managed to generate 100 new lines of enquiry and I want to thank residents for their assistance so far. I also want to thank a number for former police officers who have come forwards to offer information.”
She added: “A common description of a person of interest which has come from some of the calls has been of a man wearing a brown, potentially duffel, type coat with dark hair who was seen on the canal towpath.
“He was described as carrying a bag by some witnesses and was possibly of what was described as a scruffy or ‘student type’ appearance.
“Witnesses describe seeing potential suspects in the area of the canal at around the time of the murder and then in the Denby Dale road area after 4.45pm, and then into the evening.
“Did you know anyone fitting this description who may have lived or been in the area at the time? Anyone who has information about this man or may have known him at the time is asked to contact us.”