NEW witnesses have come forward in the case of missing schoolgirl Moira Anderson, as a final effort to locate her remains gets underway.

A major police operation is expected to begin this week to search sites where the body of the 11-year-old from Coatbridge might have been hidden after she vanished 60 years ago – starting on a 100-metre stretch of the Monkland Canal.

Sandra Brown, founder of the Moira Anderson Foundation, a charity set up in her memory to support victims of childhood sexual abuse, said she believed the new search was the closest yet to finally finding out what happened to the child.

She also revealed new witnesses have come forward in the wake of a memorial service held by the charity last month to mark the anniversary of the Moira’s disappearance, which was attended by Moira’s sister and cousin.

It is understood one of these witnesses has been able to shed new light on the schoolgirl’s last known movements.

Four years ago a grave in Old Monkland Cemetery in Coatbridge was exhumed as part of the search for Moira, but no evidence was found that she was buried there.

Brown, whose late father Alexander Gartshore is believed to have been Moira’s killer, said the search due to get underway this week is the “closest we have ever been” to finding out what happened to her.

She said: “A few years ago we thought we would have a result at Old Monkland Cemetery and then our hopes were dashed.

“But following the unsuccessful exhumation we had a steady stream of witnesses emerging and, quite strangely, even in the past fortnight that has happened again.”

The new search involving teams of scientists and forensic experts from around the UK will focus on examining six possible sites around Carnbroe, on the edge of Coatbridge, where Moira’s remains might be located.

In 1957 a witness from Carnbroe reported seeing a tall man – whose description was a good match for Gartshore – carrying a large, heavy sack towards the canal the morning after Moira disappeared. However officers at the time failed to follow this sighting up.

Gartshore, then 36, was driving the bus on which Moira was last seen on the afternoon of February 23, 1957. A few weeks after she vanished he was jailed for the rape of his family’s 13-year-old babysitter.

He died aged 85 in 2006, and was never charged in relation to Moira's disappearance – but in 2014 was named as her likely killer by then Lord Advocate, Frank Mulholland QC.

His daughter said it was surprising that the police did not drag the canal at the time of Moira’s disappearance.

She said: “It is of interest, that place, for a number of reasons – including the fact a bus route is extremely close by.

“Several of the locations are at the end of bus routes, which in those days were very rural and isolated.”

She added: “[This search] is important so her family do know exactly what happened – painful as that might be.”

A Police Scotland spokeswoman said she was unable to confirm exactly when the search was getting underway or any information about new witnesses.