By Bill Heaney
Pedophile Norman Duncan died suddenly at his home in Vale of Leven last week leading to unconfirmed speculation that he murdered and buried the body of his step-daughter Mary, who was last seen in the Bonhill community where she lived more than 44 years ago.
Over the past two years, a number of police searches for Mary Duncan’s grave have been carried out in the grounds of Vale of Leven Hospital in Alexandria and at at private properties in Helensburgh where 75-year-old Duncan, pictured right, had worked as a jobbing gardener.
The view that Norrie Duncan was the murderer was considered an open secret in the community, but he would never admit it to the police, who put him behind bars for five years for a number of serious sexual crimes.
Police Scotland confirmed to journalists a week ago that their officers had been called to an address in the Bonhill following the sudden death of a man.
There were “no suspicious circumstances,” they said, and added that a report had been sent to the Procurator Fiscal.

Mary Duncan, pictured at the age of 16, when she went missing in 1976.
Police would not confirm then that the searches were linked to disappearance of 17-year-old Mary, but her sister Mandy, said at the time: “We are praying that there is something in that house which will lead us to Mary and bring us closure. All we can do now is wait — we just want it to be over.”
In 2016, Duncan was convicted of impregnating a 15-year-old girl and sexually abusing three children nearly half a century earlier.
He was found guilty of a total of six charges involving four girls aged between eight and 15, all committed between the 1960s and 1970s, and received a five-year prison sentence, but he went home to Ladyton when he was freed.
Police tried time to find evidence and again to bring the matter into the public domain and four years ago Mary’s sisters, Debbie Renwick, Mandy Duncan and Marion McFarlane, pleaded for information.
Mary’s sisters appealed for help to find her.
They were devastated that Mary, whom they described as “a devoted mother” and “a quiet, happy girl” had vanished without a trace after leaving Bonhill, on March 19, 1976, to visit a friend in Tullichewan.
Mary had left behind her daughter, Laura, who was born on February 17, 1975, and who tragically died of natural causes the following year.
A police vehicle in West Argyll Street, Helensburgh, where police they thought Mary may have been buried.