Excavation work being carried out at a quarry as part of an investigation into the disappearance of a woman and her young son in 1976 is almost complete.
Renee MacRae, 36, from Inverness, and her three-year-old son Andrew disappeared on 12 November that year.
Police began draining Leanach Quarry in Cullloden in May. Since then more than 100,000 tonnes of earth, silt and other material has been removed.
The work is expected to be completed by the end of this week.
Approximately 55 vehicles have been uncovered from the site, but police say they are not linked to the investigation.
A substantial amount of material at the bottom of the quarry is still to be forensically searched for evidence.
It is also estimated that about 13 million litres (2.9 million gallons) of water has been drained and pumped to a nearby field.
Det Insp Brian Geddes, who is leading the investigation, said: “This is likely to take a number of weeks to complete but we are confident that if the remains of Renee and Andrew, or any other key pieces of evidence, were disposed of in the quarry, we will find them.
“The forensic search of the quarry has been a significant undertaking. We have almost completed the excavation process but there remains a vast quantity of material that still requires to be sifted and thoroughly searched.”
Renee and Andrew MacRae: Timeline
17:00, 12 November 1976:After dropping off her eldest son, Gordon, at Mr MacRae’s home, Mrs MacRae and Andrew leave Inverness for Perth.
22:00, 12 November 1976:Mrs MacRae’s BMW car is found on fire by a passing bus driver about 12 miles (19km) south of Inverness. The car is parked on a loop road that was being used as a lay-by during the construction of then new A9 trunk road. Blood is found in the boot of the car. But there is no sign of the mother and son and police begin what would become one of the UK’s longest missing persons investigations.
1976:In the fortnight following 12 November, more than 100 police officers and large numbers of volunteers search moorland around the site of where the car was discovered. RAF Canberra aircraft make wider sweeps of the area.
1977:Divers search flooded Leanach Quarry, a known fly-tipping spot, near Inverness.
August 2004:Police return to Dalmagarry Quarry, which was searched at the time of the mother and son’s disappearance. Northern Constabulary drafts in forensic archaeologists and anthropologists to sift 35,000 tonnes of soil from the disused quarry, near the lay-by where Mrs MacRae’s car was discovered, but no sign of the mother and son is found. New tests are also carried out in a laboratory in Aberdeen on traces of blood found in the boot of the BMW.
2016:A report naming a suspect who may have killed the pair is sent by Northern Constabulary to prosecutors but they decide there is insufficient evidence to take action.
October 2018:For about a week, Police Scotland divers examine Leanach Quarry using a remotely operated vehicle.
9 October:To mark Andrew’s 45th birthday, police release a photograph of him and an image of the Silver Cross pram owned by his mother. Officers appeal for sightings of the pram on and around 12 November 1976.
28 May 2019:Work to pump water from Leanach quarry begins.
10 June:Leanach quarry is drained clearing the way for silt and debris to be removed for forensic tests.
25 June:Parts of a pram found in the quarry and sent for forensic tests.