The brother of a schoolgirl who was murdered 25 years ago has “implored” anyone with information to come forward and help achieve justice for her.

Kate Bushell, 14, suffered a fatal knife wound to her throat in an attack in fields just 300 yards from her home in Exwick, Exeter, Devon, on November 15 1997.

Her father Jerry discovered the teenager’s body in a field off Exwick lane at 7.30pm – around three hours after Kate had left to walk a neighbour’s Jack Russell dog named Gemma.

Detectives, speaking on the 25th anniversary of Kate’s death, said they are convinced someone holds the final clue to bring her killer to justice.

A £20,000 reward has been offered by independent charity Crimestoppers for information which leads to the arrest and conviction of her attacker.

Tim Bushell, Kate’s older brother, called on anyone withholding information about the case to look to their conscience and speak out.

“Twenty five years ago my 14-year-old sister Kate was taken from my family and me when she was murdered near our home whilst walking a friend’s dog,” Mr Bushell said.

“There isn’t a day that goes past where my family and I don’t think of her, what life would be like if she hadn’t been taken from us, what she would have achieved, and all the family milestones that we have been unable to include her in.

“Over the past 25 years thousands of enquiries have been undertaken by the police. They have information that needs clarification, but we are still waiting for the key breakthrough.

“I would implore anyone who has been unable to do so previously to share any information with the police so that with your help they can apprehend the person responsible and achieve justice for Kate.”

The killing of Kate, who attended St Thomas High School, is one of the largest and longest-running unsolved murder enquiries run by Devon and Cornwall Police.

More than 160 detectives and staff were deployed to the case in 1997, with more than 5,000 house-to-house interviews conducted and over 5,000 DNA samples taken from people in the area.

Three suspects have been interviewed and released without charge.

In 2017, police launched an investigative review alongside a public appeal to mark the 20th anniversary of the murder.

This generated 204 calls and messages into the incident room, identifying 10 new lines of enquiry.

However, detectives say they still need the vital clue on which to build the case.

Detective Inspector Rob Back, of Devon and Cornwall Police, said: “It has now been 25 years since this truly terrible murder but we have never forgotten Kate. We are as committed as ever to bringing the person responsible to justice.

“We appreciate that 25 years is a long time but someone must know what happened that day. For whatever reason they have not come forward but it is not too late to do so now.

“My hope in making this renewed appeal is to ask once again for that vital piece of evidence we need to trace the killer and bring much-needed closure for Kate’s family.”

On the day of the murder, Kate left her home in Burrator Drive to walk her neighbour’s dog at about 4.30pm.

She was last seen alive at 4.50pm by a layby near the Whitestone Cross end of Exwick Lane.

Witnesses recalled seeing Kate and Gemma, the dog, but also a small blue car parked in a nearby stables layby with a man standing by it.

People also reported seeing a man running in the Farm Hill/Cornflower Hill area of Exwick that evening. He has never been traced.

At 5.30pm, a small dog believed to be Gemma was seen running loose from a gateway in Exwick Lane at the base of the field where Kate’s body was found.

Kate’s body was discovered at 7.30pm. She had suffered a catastrophic injury to her neck caused by a blade measuring at least six inches long.

Orange clothing fibres – from a material predominantly used in non-fluorescent workwear such as boiler suits, aprons and gloves – were found on Kate’s body and a nearby country stile.

Mr Back said it is believed the murderer may have lived locally or had links to friends or family in the area as the location of Kate’s murder is not common to people outside the area.

He added: “I remain convinced that either somebody knows or suspects who is responsible for Kate’s death.

“Maybe someone had suspicions about someone in their life back then and has been protecting them out of misplaced loyalty. It is now time for those allegiances to change.”

Information can be reported through Devon and Cornwall Police’s Major Incident Public Portal online, or through Crimestoppers anonymously.