Corrie McKeague's mother had said it "seems so unlikely" that her son is still alive
As a search team investigating his disappearance trawled through 60 tons of waste at a landfill site, Gunner McKeague's mother Nicola Urquhart said she was "terrified" of what they might find.
Her 23-year-old son, from Fife, vanished on a night out with friends in Bury St Edmunds, Suffolk, on September 24.
A bin lorry was seen on CCTV near Brentgovel Street in the town around the time Gunner McKeague was last seen, and it took a route which appeared to coincide with the movements of his phone.
It was relief but at the same time really, really worried and terrified that they may find something
Mrs Urquhart said that his family have pushed for the landfill site to be searched "from the very beginning" of the investigation, and that she was relieved the police had decided to do so.
She said that she was "terrified that they might find something but at the same time so relieved because from the very beginning it's been the most obvious and it has been the only bit of information, really intelligence, that they've ever had, that Corrie's phone travelled in the same place as the bin lorry."
"It was relief but at the same time really, really worried and terrified that they may find something."
A search team trawled through 60 tons of waste at a landfill site
She added: "I think it would be quite unrealistic for me to presume that Corrie could still be alive," but said "thinking that and believing it are two completely different things.
"Just now my absolute focus is on trying to keep it together for long enough to find Corrie."
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It could take the team of eight trained search officers up to 10 weeks to sift through rubbish up to 27 feet deep, covering around 9,900 square feet of the dump in Milton, near Cambridge.
MISSING RAF serviceman, Corrie Mckeague Mon, January 9, 2017
Corrie Mckeague, of Dungermline, Fife, has been missing since he disappeared after a night out in Bury St Edmunds, Suffolk on September 24. The 23-year-old's girlfriend, April Oliver, 21, of Norfolk, revealed she found out she was expecting his child two weeks after he vanished near RAF Honington where he has been based for three years while training to be a gunner and a medic.
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April Oliver, 21, girlfriend of missing 23-year-old Corrie McKeague (right), who has revealed she is expecting his child
A bin lorry linked to the disappearance of Gunner McKeague was initially thought to have collected a 1st 10lb load, but police said it was later found to be more than 15st 10lb.
Mrs Urquhart has said this could "only mean one thing".
The area of the landfill site where the load was deposited is now being searched, with a digger mechanically excavating mounds of waste and officers in white protective suits raking through it on the ground.
It could take the team up to 10 weeks to sift through rubbish up to 27 feet deep
A 26-year-old man had been arrested on suspicion of perverting the course of justice over the discrepancy in the lorry's load weight.
The man, who is not the bin lorry driver, faces no further action.
Detective Superintendent Katie Elliott said she does not believe there was a "deliberate attempt to mislead" the investigation, and that the focus had to be on finding Gunner McKeague.
Corrie vanished on a night out with friends in Bury St Edmunds
The six-month investigation has cost more than £300,000 to date and the search of the landfill site could cost more than £500,000 if it runs to 10 weeks.
Supt Elliott said it was a "dreadful" time for the family of Gunner McKeague and her thoughts are with them.