Detectives searching for missing RAF gunner Corrie McKeague have found no trace of him in waste recovered from an incinerator plant.
The site at Great Blakenham, near Ipswich, was examined after the search of a landfill site at Milton, Cambridgeshire, was called off.
While the incinerator site was known to contain animal bones from food waste, no human bone material was found.
Mr McKeague, from Fife in Scotland but based at RAF Honington in Suffolk, vanished after a night out with friends in Bury St Edmunds on September 24 last year.
Police still believe the 23-year-old's remains are somewhere on the sprawling landfill site at Milton, but called off the search after 20 weeks.
A Suffolk Police spokesman said: "Suffolk police have engaged experts to examine incinerated waste gathered from the Great Blakenham energy-from-waste facility and it has been confirmed that this matter does not contain human bone material."
A review of the investigation to date will be conducted by the East Midlands Special Operations Unit (EMSOU), after concerns were raised that Suffolk Police's original choice of Essex Police was too close to the force.
EMSOU is a collaborative team uniting specialist officers and staff from the police forces of Derbyshire, Leicestershire, Lincolnshire, Northamptonshire and Nottinghamshire in tackling major crime, and serious and organised crime.
"The aim of the review is to assist in identifying whether there are any other lines of inquiry that should be pursued that could lead to information that would locate Corrie McKeague," the Suffolk Police spokesman said.
"Investigative reviews are a key part of any lengthy major investigation and we are confident this will be a detailed and impartial review.
"If this review establishes further lines of inquiry, we will pursue them."
"No timescale has been set for the completion of the review but the first phase is due to be completed by the end of September."
The force spokesman said the area of the Milton landfill that has been searched will be left "in its current state" by agreement with the company that runs the site.
"Cell 22 will not be used for the deposition of waste until the review is concluded," the spokesman said. "Corrie's mother and father have both been updated in relation to all of the above."
Police previously said Mr McKeague had a history of falling asleep in unusual places, including in bins.
A bin lorry was seen on CCTV near Brentgovel Street in Bury St Edmunds around the time Mr McKeague was last seen. 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 an 11kg (1st 10lb) load, but police said it was later found to be more than 100kg (15st 10lb).
Mr McKeague's girlfriend April Oliver announced in June that the missing serviceman had become a father with the birth of their daughter.
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