The family of missing Fife airman Corrie McKeague has won a campaign to prevent a landfill site at the centre of the search from being filled in.
Suffolk Constabulary said the search area at the site in Milton, Cambridgeshire, would not be filled in until the situation had been reviewed.
In addition, the force said incinerated waste would now be examined by forensic experts.
The move was welcomed by Corrie’s mother Nicola Urquhart, of Dunfermline.
Ms Urquhart, 48, said: “I am so pleased that Suffolk Police have heard our voices and listened.
“They have heard our concerns at the landfill being handed back and being filled in and have now said although handed back, it will not be touched and will remain in the same condition until after the review by an independent force.”
Ms Urquhart had previously considered seeking an injunction to prevent the search “cell” at the site from being filled in.
Police called off the operation at the landfill after spending 20 weeks fruitlessly sifting through waste at an area where Corrie’s body is believed to have been dumped.
After police said they had scoured the whole area which could contain traces of Corrie, thousands signed a petition to prevent the cavity from being filled in.
Corrie’s father, Martin McKeague, was photographed at the landfill site near Cambridge with his motorhome blocking the entrance.
Police said 23-year-old Corrie, who was based at Honington in Suffolk, had a history of falling asleep in unusual places, including in bins.
A bin lorry was seen on CCTV near Brentgovel Street in the Bury St Edmunds around the time Mr McKeague was last seen after a night out with friends last September, and it took a route which appeared to coincide with the movements of his phone.
The bin lorry linked to the disappearance of Mr McKeague was initially thought to have collected a 1st 10lb load, but police said it was later found to be more than 15st 10lb.
The search, which began in March, was halted last week after no trace of the serviceman was found.
A Suffolk Constabulary spokesman said: “The search for Corrie remains a live and active investigation as we all remain committed to finding him.
“We have exhausted the search as to where Corrie is mostly likely to be at the landfill site at Milton, although we acknowledge and understand the frustration that Corrie’s family, friends and many supporters feel in relation to this.
“We will now take time to pause and reflect where we are with the investigation and will continue to carefully review it as we have done from the outset.
“With this in mind while we no longer have an operational presence at the site at Milton, the police have agreed with the company that run the site to leave cell 22 in its current state and will not be using it for the deposition of waste until the review is concluded.
“As said on Friday, we will now commission an external police force to carry out an independent review of the investigation.
“The identity of the force that will conduct this is still to be established as we are eager to ensure that it is a force that satisfies the need for complete transparency and independence.
“We are confident this will be a forensic, detailed and impartial review that will leave no stone unturned. If this review establishes further lines of enquiry we will pursue them.
“We reiterate that although it is not a criminal investigation, our work to locate Corrie remains ongoing.
“This will include work to search preserved waste that was incinerated to see if this will establish if there are any further clues as to what happened to Corrie. This incinerated waste will be subject to examination and where necessary forensic analysis in the coming weeks.”