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.

The 23-year-old joined Wolves for a fee of £185,000 from Castleford in 2014.
Clark score 10 tries last season as Warrington won the League Leaders' Shield and reached the Grand Final, and played for England in the Four Nations.
"I believe we're building something special here as a club and a team," he told the club's YouTube page.
"I'm just looking forward to being part of that for the next few years..

Manager Roberto Martinez wants greater attacking options after selling Steven Naismith to Norwich and Aiden McGeady also possibly going out on loan.
Everton's top target was Dynamo Kiev forward Andriy Yarmolenko but they have been frustrated in that pursuit.
Senegal striker Niasse has 12 goals in 21 games for his club this season.
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