DETECTIVES are searching the grounds of the Vale of Leven Hospital in connection with the disappearance of Mary Duncan more than four decades ago.

Police Scotland confirmed they were following extensive enquiries and would be searching a number of sites for "a number of weeks".

Mary disappeared at the age of 17 from her home in Bonhill in 1976 and there has never been a trace of her since, leaving her family distraught with the mystery of what happened.

Detective Superintendent Calum Young, from West Dunbartonshire CID, said: “Mary left her home at 17 years of age, with no money and has never claimed benefits, paid tax or national insurance. She also left behind her baby girl Laura, who family say she absolutely adored.

“Extensive enquiries continue in an attempt to find any indication of where Mary could be, however due to the fact that she has not been seen or heard from in 42-years, we must consider the option that she may have come to harm.

“Specialist officers will be searching a number of locations at the Vale of Leven Hospital in connection with the investigation.

“I would like to take this opportunity to remind members of the public and the media that this is still a functioning hospital and disruption must be kept to an absolute minimum.

"It is also vital that the search team are left to get on with this important work and any updates will be provided in due course.”

Read more: Police could dig in search for missing Mary Duncan

Marie Farrell, director of Clyde Sector at NHS Greater Glasgow and Clyde, said: “We have been working with Police Scotland on the planned excavation of a number of sites in the grounds of the Vale of Leven Hospital. "We would like to reassure patients that there will be no disruption to patient care as a consequence of these enquiries.”

Mary was the oldest of the children and worked as a machinist in Rosshead, disappearing after visiting a friend in Tullichewan.

She gave birth to Laura on February 17, 1975 but left home without her on March 19, 1976. She has never been seen or heard from again.

Laura died of natural causes in October 1976.

Detectives in 2018 said Mary was known to frequent the grounds of the Vale of Leven Hospital and appealed for any patients or former employees to get in touch if they saw her that day.

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