A FINAL effort to find the remains of Coatbridge schoolgirl Moira Anderson, who vanished 60 years ago, will begin on a 100-metre stretch of the Monkland Canal next month.

An unprecedented police operation involving teams of scientists and forensic experts from around the UK will conclude with a step-by-step search of six possible sites where Moira, who was 11, might have been hidden.

The canal will be the starting point as it has the strongest evidential link to Moira and to a man who matches the description of her likely killer, the late Alexander Gartshore.

Police officers have met twice this year with experts from universities including Aberdeen, Dundee, Belfast and Birmingham, alongside specialists from the Home Office, to plan the final hunt.

Maps of the areas of interest, which centre around Carnbroe, on the edge of Coatbridge, have been overlaid with aerial photographs taken of the terrain from 1945 onwards, allowing investigators to plot and analyse how the terrain has changed over the decades.

The oldest images, held by the National Archives, were frozen and had to be thawed out for detectives and experts to examine them.

The search will begin on or around March 13, focusing at first on a 100-metre stretch of the canal. If it yields nothing, the operation will move to the first of five potential sites on land nearby.

Ground-penetrating radar and sonar equipment will be deployed initially, but police will go into the canal to examine close-up anything of interest.

Experts will be on hand to advise on damming and draining parts of the canal, if necessary, and others on how to remove any human remains. or items like fabrics, without destroying them – a real concern after decades in an environment without oxygen.

Police Scotland received hundreds of fresh leads during a high-profile re-investigation of the case that started four years ago, but the evidence pointing to the canal has always been available. Officers searching for Moira in 1957 failed to follow up with a witness from Carnbroe who saw a tall man, of about 35, emerging from waste-ground opposite his home, carrying a large, heavy sack towards the canal the morning after Moira disappeared.

The witness reported the sighting to police and his description was a good match for Gartshore, named in 2014 as Moira’s likely killer by then Lord Advocate, Frank Mulholland QC.

Gartshore, then 36, was driving the bus on which Moira was last seen on the bitterly cold, snowy afternoon of February 23, 1957. He died aged 85 in a Leeds hospital on April 1, 2006, never having been charged in relation to Moira’s disappearance.

The failure by police then even to question Gartshore is remarkable because he had been charged with raping his family’s 13-year-old babysitter. A few weeks after Moira vanished he was convicted of the rape and jailed.

Years later his daughter, Sandra Brown, linked Gartshore publicly to Moira in a book, Where There is Evil.

Just before he died she visited him in hospital. Although he stopped short of confessing, he said Moira had haunted him his whole life, and had been "too bonny for her own good".

Brown set up the Moira Anderson Foundation, based in Airdrie, to support the victims of child sexual abuse.

She has become a close friend of Moira’s sister, Janet Hart, who lives in Australia and is now the charity’s patron.

Hart is coming to Scotland to mark the 60th anniversary of the loss of her sister and will attend a memorial event at the Foundation’s HQ on Thursday.

She said last night: “I am trying not to get my hopes up, but I can’t help feeling the time has come.

“I’m so grateful to Sandra for keeping Moira in the public eye, to the police and experts who have left no stone unturned these last few years and to Frank Mulholland for refusing to let matters rest.

“If the police in 1957 had shown the same commitment, we’d have found Moira long ago.”

There have been murmurings of discontent in some quarters about the resources devoted to such an old case, especially as the likely perpetrator is long dead.

But Det Supt Pat Campbell, who is leading the investigation, said: “What price would any of us place on the recovery of a child’s body to bring closure to a grieving family?

“There has never been any doubt this was the right thing to do. It’s always been a needle in a haystack, but by getting together the right experts we’ve given ourselves a chance. The commitment the experts have shown to trying to bring this to a successful conclusion has been remarkable.

“We will either find Moira, or almost certainly be forced to conclude we’ll never get her back. We’ll do all we can to make sure it ends well. We know we’re playing out the last act.”