Suffolk Police say no human remains have been found after they investigated material from a waste incinerator in the search for Corrie McKeague.
The airman from RAF Honington went missing after a night out in Bury St Edmunds in September 2016.
The search had been centred on a landfill site at Milton in Cambridgeshire after fears that Corrie may have fallen asleep in a rubbish bin and been transported away in a bin lorry.
At the beginning of August, police searching incinerated waste at the Great Blakenham energy-from-waste facility near Ipswich say they've recovered material that requires further examination in order to establish whether it is in any way connected to the missing person enquiry.
But police have now ruled out human remains in the ash.
Suffolk Police have also confirmed that the way the case has been handled will be investigated by East Midlands Special Operations Unit to identify if there are other lines of inquiry to follow up in the hunt for Corrie McKeague
Suffolk Police no longer have an operational presence at the landfill site in Milton.
The company which runs the site has agreed to leave the focus of the search area in its current state with no further rubbish dumped there until the review is concluded.
Corrie's parents have been told of the latest developments.