Searches of Leanach Quarry near Inverness remain ongoing as part of the investigation into the murder of Renee and Andrew MacRae.
The excavation phase of the operation is expected to be completed this week, although a substantial amount of material is still to be forensically searched for evidence.
Since work started at Leanach Quarry in May more than 100,000 tonnes of earth, silt and other material has been removed from the site, with 5,000 tonnes for forensic searching.
Approximately 55 vehicles - none linked to the enquiry - have also been uncovered during the excavation phase.
Detective Inspector Brian Geddes said: "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.
"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 process of backfilling sections of the quarry where excavation has taken place has commenced and again this will continue over a matter of weeks.
" I would like to thank everyone that has been involved in the operation to date, and the surrounding community for their patience while this has been ongoing.
"We remain determined to bring this matter to a successful conclusion and we continue to progress all relevant lines of enquiry.
"I would urge anyone who we have yet to speak to, and who has information, to please come forward and contact us.”
Anyone who believes they can assist Police is asked to contact 101 or you can e-mail a dedicated inbox at SCDHOLMESInverness@scotland.pnn.police.uk. You can also contact Crimestoppers anonymously on 0800 555 111.