DETECTIVES investigating the disappearance of a teenager more than 40 years ago have begun searching a number of sites at the Vale of Level Hospital in Alexandria. 

Police Scotland began the searches at two sites at the hospital today in the latest development of the case into missing Mary Duncan. Officers said the searches will continue for a number of weeks. 

Mary was 17-years-old when she disappeared from her home in Alexandria in 1976.

Mary, who had a 13-month-old daughter, vanished after telling her family she was going to meet a friend. Her baby later died of natural causes.

Police Scotland said extensive enquiries have been carried out in an attempt to establish any information regarding Mary’s whereabouts, however no trace of her has been found.

READ MORE: Family tell of hope over sister missing since 1976 ahead of her 60th birthday

Glasgow Times:

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.”

Glasgow Times:

Her family previously spoke of the police's plan to excavate the area.

Sister Debbie Rennick previously: "Over the years we've come to realise she is no longer alive. But this investigation gaining momentum has given us hope that we might get some kind of resolution."

Marie Farrell, Director of Clyde Sector, 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.”