Police investigating the murder of a teenager 21 years ago believe locals have been reluctant to come forward with information.

Caroline Glachan, 14, was found dead in the River Leven in Renton, West Dunbartonshire, on Sunday, August 25, 1996.

Police announced a reinvestigation into the case a year ago and detectives are certain the answer to her murder lies in the local community.

Detective superintendent Jim Kerr, senior investigating officer, said: "It's now been a year since we announced the re-investigation into Caroline's murder.

"A good amount of progress has been made since then and we've been working very closely with forensic scientists at the Scottish Crime Campus.

"A large number of the 300 pieces of evidence continue to be carefully examined for traces of DNA and the painstaking work that the scientists have been carrying out continues.

He added: "Following our reappeal, we've had calls from as far away as Australia with information, from people who lived in the area of Bonhill and Renton at the time of the murder.

"Our work over the last year has continued to review the initial investigation and visiting those who were witnesses at the time to take reference samples of DNA."

Police remain in contact with Caroline's mother Margaret and appealed to anyone with information that will assist the investigation to "do the right thing" and come forward.

Mr Kerr said: "I know there has been a reluctance from people in the Bonhill and Renton areas to come forward in the past with vital information on this murder.

"However, can I remind people that we are investigating the murder of a 14-year-old girl - a young girl who is sorely missed by her family and friends.

"Someone out there who stayed in that community at that time holds the vital information we need - there is no doubt in that."

Caroline's friend Joanne Menzies was one of the last people to see her when they parted at Bonhill shops at 11.54pm.

The 14-year-old was last seen at about 12.15am when she walked down Dillichip Loan towards Dillichip Bridge - known locally as the black bridge - and then on to the towpath.

Detectives are keen to trace a man who was wearing a dark green hooded top who was seen by a taxi driver walking near Caroline at 12.15am on the night she disappeared.

Mr Kerr said: "The man has sharp features and may well be the last person to see Caroline alive. However, despite previous appeals to identify him, he has never been traced.

"Witnesses have also spoken of hearing people arguing or shouting in that area a short time later."

Anyone with information is asked to contact police on 101.