Renee and Andrew MacRae: Pushchair parts at Culloden quarry

Parts of a pram have been found in a disused quarry drained in a police investigation into the murder of a mother and her young son 43 years ago.

Renee MacRae, 36, from Inverness, and her three-year-old son Andrew disappeared on 12 November 1976.

Andrew's Silver Cross pram is among personal items that also vanished.

The wheels found are similar to those used on the boy's pram and are now the subject of "meticulous research and examination" by police.

Debris at the bottom of Leanach quarry at Culloden, near Inverness, is being forensically examined.

Bones have also been recovered from the known fly-tipping site, and were believed to be those of an animal, though police said the remains will be the subject of further examination.

Det Insp Brian Geddes said: "As part of the search operation at Leanach Quarry numerous items have been found to date, many of which have warranted further research and examination.

"Meticulous analysis is now ongoing to establish if any of these items would be relevant to the investigation into the murders of Renee and Andrew MacRae."

An estimated 13 million litres of water was pumped from the flooded quarry to allow for silt and debris to be removed for forensic testing.

On the evening of her disappearance, Mrs MacRae, who was estranged from her husband Gordon, had set off for Perth with the youngest of her two sons, Andrew, to meet her lover Bill McDowell, Mr MacRae's married accountant who also lived in the Inverness area.

Mr McDowell told police they never met.

Mrs MacRae's burnt-out BMW car was discovered on the night she disappeared in a lay-by on the A9 south of Inverness.

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.