Detectives investigating the disappearance of a teenager who vanished over 40 years ago are to extend their search into a residential area in Helensburgh.

Mary Duncan was 17-yeas-old when she disappeared from her home in Alexandra in West Dunbartonshire in 1976. 

She vanished after telling family she was going to meet a friend. Her 13-month-old daughter died a short while after her disappearance from natural causes.

Extensive enquiries have now been carried out in a bid to establish any information regarding Mary's whereabouts - however, no trace of her has been found. 

Police Scotland began searches at two sites at the Vale of Leven Hospital in August in their latest develoments of the missing person case. 

READ MORE: Sites at Vale of Leven hospital to be searched for missing Mary Duncan who vanished more than 40 years ago

Searches of the new Helensburgh side - which is a residential area - will commence today. 

Detective Superintendent Calum Young from West Dunbartonshire CID said: “This latest development is due to extensive enquiries carried out in an attempt to find any indication of where Mary could be.

“This new site is within a residential area and as such I would like to stress that any disruption to local residents must be kept to a minimum, and would ask both the media and public to remain mindful of this.  

"Any updates from the new search site will be provided in due course.”