Detectives searching for teenage Mary Duncan who went missing 43 years ago could dig in West Dunbartonshire, the BBC is reporting. 

The 17-year-old disappeared from her home in Third Avenue, Bonhill, on March 19, 1976 without her young child, Laura, and has never been seen or heard from again.

Her sisters made an emotional appeal for information last year as detectives renewed work on the case.

The BBC said Mary’s sisters told them police were preparing to excavate land in the area.

Marion McFarlane told them: “We should be having a birthday party, buying balloons and celebrating Mary's 60th birthday with her and her children and maybe grandchildren.

"That's a whole generation that is missing from our family. Our grandkids are growing up and every time we have a birthday or anniversary we are reminded Mary's not here and her kids and grandkids are not here."

Mary was the step-daughter of Bonhill child abuser Norman Duncan, who detectives revealed they had interviewed in connection with the case.

But they insisted it remained a missing person case.

Detective Superintendent Calum Young said Mary was known to have frequented the grounds of the Vale of Leven Hospital and they were particularly keen to hear from former staff or residents who may have seen Mary.

Dumbarton and Vale of Leven Reporter: (Left to right) Debbie Rennick, Mandy Duncan and Marion McFarlane the three sisters of 17-year-old Mary Duncan, who went missing 41 years ago, as the trio make a public appeal for information to try and find out what happened to her at a media briefing at

Speaking at the press conference with Mary’s sisters in July 2018, Det Supt Young said “At the age of 17, Mary was a devoted mother to a baby girl called Laura. Her family say Mary absolutely adored her daughter and that her disappearance, and leaving Laura behind, was completely out of character.

“Mary left home with no money and she has never claimed benefits, paid tax or national insurance. Her family strongly doubt that she would have had the means or life skills to start a new life and live independently.

“Whilst there is no evidence to suggest that Mary came to any harm, due to the fact that she has not been seen or heard from in 41 years, we can’t rule this out.

“Mary’s family were left completely devastated by her disappearance, a pain which lives with them to this day, and it is vital that we get to the bottom of what happened to their sister and provide them with some closure.

“I believe the answer to what happened to Mary lies within the local community.”

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

Her daughter Laura died of natural causes in October 1976.

The BBC reported that Mary’s sisters returned to Third Avenue and tied ribbons to remember her.

This week would mark Mary’s 60th birthday.

Police Scotland told the BBC: "This is an ongoing inquiry and we are in regular contact with the family."