Moira Anderson was 11 when she went missing from her home in Coatbridge, North Lanarkshire, in February 1957 while running an errand for her grandmother.
In 2014, prosecutors took the unprecedented step of announcing that local bus driver and convicted paedophile Alexander Gartshore, who died in 2006, would have faced prosecution for the schoolgirl’s murder if he were still alive.
A reinvestigation set up in 2013 identified six potential deposition sites in Coatbridge, with a 170m area of Monklands canal the priority.
Specialists in sonar scanning, ground-penetrating radar and magnetometry began scouring the area last week for any sign of remains, jewellery or clothing and have now established five “areas of interest” within the canal that divers will now investigate further.
Speaking ahead of yesterday’s search, a Police Scotland spokesman said: “The conclusion of this first scoping phase has resulted in five distinct areas of anomalies being identified by specialist resources.
“The second phase of this operation will commence on Monday with divers from Police Scotland’s marine unit, conducting a search of the identified areas.
“The second phase of the operation will focus on identifying and removing relevant items located within the established areas of interest.”
Those involved in the search and analysis of material found include forensic soil expert Professor Lorna Dawson and Professor Sue Black, director of anatomy and human identification at the University of Dundee.
A plot in Old Monkland Cemetery, Coatbridge, was previously searched by experts but the search failed to find Moira’s remains.
Police had been investigating the possibility Gartshore dumped the youngster’s body in the grave of an acquaintance named Sinclair Upton.
Last week, Detective Superintendent Pat Campbell said he hoped to finally bring closure to the case with the canal search. He said: “The land round about [the canal] has not changed much in 60 years. We know it’s been dredged three times but that’s taken place only really at the sides of the canal in general. We remain optimistic that we can recover her remains.”