Corrie Mckeague, 23, vanished after a night out in Bury St Edmunds, Suffolk, on 24 September.
Experts from McKenzie Intelligence Services were brought in to assist Suffolk Police after Â£51,000 was raised through an online crowdfunding page.
Forbes McKenzie said his team would add "clarity" to the investigation.
What do we know about Corrie Mckeague's disappearance?
He said: "Our mission is to create clarity from the huge amount of data that has emerged.
"We think the phone is a key piece of information.
"Where the phone finished is indicative of where Corrie was last.
"I'm very interested in what other phones were co-located with Corrie's phone."
Mr McKenzie, whose company is based in London, said he had three specialists, including himself, working on the case.
He stressed his team was "not running a parallel investigation" to Suffolk Police but was there to "add value" to what the force was doing.
The team's first task would be to collate all of the information available on social media feeds, CCTV and areas that have and have not been searched, he said.
"We are plugging the gaps that Suffolk Police just doesn't have the people power to do.
"This investigation might prove to be the very first crowdfunded and crowd-data sourced investigation," Mr McKenzie added.
About 5,000 people pledged support to the crowdfunding page after the family of Mr Mckeague, from Dunfermline, Fife, expressed concerns about the police investigation.
The RAF Honington gunner was last seen at about 03:25 BST walking alone in the Suffolk town.
A second public search for Mr Mckeague will take place on 22 January. More than 60 volunteers joined in the first on 17 December.
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