Police investigating the disappearance of Corrie McKeague are probing whether a bin lorry carried the RAF gunner to a landfill site.
Mr McKeague, 23, from Fife, vanished on a night out with friends on September 24 in Bury St Edmunds, Suffolk.
CCTV shows a waste lorry made a collection in the area he was last seen shortly after the last confirmed sighting of him, while the vehicle's route appeared to coincide with the movements of his phone.
Suffolk Police said the search of the area was the "next logical step" after the vehicle's waste load was found to be far heavier than first thought.
Despite initial suggestions that the load of the lorry was 11kg, police said it was found to be more than 100kg.
Forensic examinations previously found no traces of Mr McKeague in the lorry.
The last CCTV sighting of Mr McKeague showed him walking from a shop doorway and into a horseshoe-shaped area in Brentgovel Street, with no sign of him emerging.
The drastic difference in weight prompted police to swoop on a 26-year-old man, who was not the driver, before he was bailed on March 1.
He was arrested on suspicion of perverting the course of justice by misleading officers about the weight, but on Tuesday was told he faced no further action.
He was told he will not face charges after detectives concluded he was not hiding information, police said.
Detective Superintendent Katie Elliott said: "Through the persistence of officers and their detailed work we recently identified that the data provided was incorrect.
"We now know the weight of the waste collection from the 'horseshoe' on the night Corrie went missing was over 100kg, when the original information we were given indicated that this was 11kg, and this makes our search of the landfill the next logical step to try to find Corrie.
"The investigation has identified that the company who provided the data usually charge per collection, not per weight of load collected, and it appears that it was genuinely believed by the company that the data provided was correct.
"There was no intention to mislead the investigation, however our discovery, through persisting with this through our inquiries and evidence gathering, now puts a new emphasis on the search."
The search of the landfill site in Milton, Cambridgeshire will take six to 10 weeks, covering around 920 square metres up to a depth of eight metres, police said.
It follows work to move 8,000 tonnes of bulk material to make the area safe to search.