FORMER staff of the Vale of Leven Hospital are being asked to think back more than four decades in case they could help solve a missing person case.

Mary Duncan left home at 51 Third Avenue, Bonhill, on March 19, 1976 without her young child and has never been seen or heard from again.

In a new appeal by police and Mary's sisters, Debbie Renwick, Mandy Duncan and Marion McFarlane, they said she was known to frequent the grounds of the hospital and someone might have seen her that day.

In an emotional press conference, Ms Renwick, 56, said: "Somebody must know something. Somebody must know what happened to her and we hope that person will come forward now.

"We are miserable without her. We have missed her every year. She was our elder sister."

She added: "We just want to bring her home. Please bring her back."

Ms McFarlane, 59, who has never spoken previously, said any information from the public could be "the missing piece of the jigsaw".

She said: "Mary matters a great deal even now. She would have been 60 near year. We have missed a whole generation."

Mary's disappearance was considered completely out of character, particularly leaving behind her 13-month-old baby Laura, who died of natural causes in October 1976.

Detective Superintendent Calum Young said: "Some of our enquiries have focussed on the Vale of Leven Hospital and I would appeal to anyone who worked there in 1976 to come forward as they may be able to assist with out investigation.

"Mary's family have waited long enough for answers. Please, if you have any information at all, contact Dumbarton Police Station on 101."

Mary was last seen around tea time wearing a midi length navy skirt, black platform shoes, green hooded zipper, black and white dogstooth coat.