The mother of missing airman Corrie McKeague has said she is "trying to keep a sensible head on" after bones that could be his were found in a Suffolk river.
Nicola Urquhart has said that police have been unable to reassure her that human remains found in bin bags in the River Stour in Sudbury on 27 August are not her son's.
No trace of the 23-year-old has been found since he was last seen in Bury St Edmunds, Suffolk, on 24 September, 2016.
Corrie McKeague was stationed at nearby RAF Honington at the time he went missing.
Suffolk Police said although further tests on the bones were taking place, a post-mortem examination "was not able to establish any form of identification or cause of death".
They had no further comment to make about whether or not the remains could be Corrie McKeague's.
Ms Urquhart told the East Anglian Daily Times: "Most times when remains or bodies have been found, the police down in Suffolk have been able to put my mind at rest that it's not Corrie very quickly.
"After speaking to me, they’ll be able to tell me that they already think they know who the person is or, for whatever reason, they know it’s not Corrie.
"Unfortunately, on this occasion, they’ve not been able to do that.
"So I think the hard thing is that, whether this is Corrie or not, this is somebody’s son or daughter – and it’s whether anybody will ever find out because they might not be able to identify who this person is."
She added: "It’s just about trying to keep a sensible head on, and not letting your head start making things up and thinking a million thoughts.
"It is really difficult just to wait until you get an answer because there’s as much chance of this not being Corrie as it being Corrie but it’s going to be someone’s son or daughter.
"It’s just awful."
No trace of the airman has been found since his disappearance.
The case was handed over to cold case detectives in 2018.