Investigators working to find the body of missing schoolgirl Moira Anderson will make a decision "in due course" on the areas to be searched for her remains.

Experts said they have been able to narrow down the number of possible areas where the 11-year-old's body may have been buried thanks to specialist analysis in the field of soil science.

The latest remarks from the Crown Office followed a "positive" meeting in Edinburgh today between Lord Advocate Frank Mulholland, police and forensic expert Professor Lorna Dawson as they prepared to consider the next steps in the investigation into the 58-year-old murder case.

Moira disappeared from her home in Coatbridge, North Lanarkshire, in February 1957 while running an errand for her grandmother.

Prosecutors last year took the unprecedented step of announcing that convicted paedophile Alexander Gartshore, a bus driver who died in 2006, would have faced prosecution for the schoolgirl's murder if he were still alive.

Earlier this year, the Crown Office enlisted the help of Aberdeen-based forensic soil scientist Prof Dawson as part of efforts to find Moira's remains.

Last month, they received an initial soil report but said further work had to be carried out before the search could move to the next stage.

Reports suggested her team wants to search a new site north of Coatbridge where a farm worker reported an empty bus blocking a lane on the night the schoolgirl disappeared.

Following today's meeting, a Crown Office spokesman said: "The Lord Advocate held a positive meeting with forensic expert Professor Lorna Dawson of the James Hutton Institute and DS Pat Campbell of Police Scotland, and the Crown will now consider the next steps in the investigation into the murder of Moira Anderson.

"Specialist work in the field of soil science and geographical information has allowed investigators to narrow down the number of possible locations for the whereabouts of Moira's remains and a decision on the search areas will be made in due course."

Coatbridge bus driver Gartshore, who was 85 when he died, was the last person to see Moira alive and had long been connected with the case.

The Lord Advocate has instructed the investigation remains open in the hope that one day Moira's body may be found and her family given closure.

Prof Dawson, who runs a lab dedicated to forensic soil science, has worked on dozens of cases from around the world.