The mother of missing RAF gunner Corrie McKeague has said it "seems so unlikely" that her son is still alive.
As a search team investigating his disappearance trawled through 60 tonnes of waste at a landfill site, Mr 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 Mr McKeague was last seen, and it took a route which appeared to coincide with the movements of his phone.
Ms 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 told Sky News 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."
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."
It could take the team of eight trained search officers up to 10 weeks to sift through rubbish up to eight metres deep, covering around 920 square metres of the dump in Milton, near Cambridge.
A bin lorry linked to the disappearance of Mr McKeague was initially thought to have collected an 11kg (1st 10lb) load, but police said it was later found to be more than 100kg (15st 10lb).
Ms 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.
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 Mr McKeague.
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.
Ms Elliott said it was a "dreadful" time for the family of Mr McKeague and her thoughts are with them.