Nicola Bulley's body is likely to be found within a two mile radius, according to dive expert Peter Faulding.
The mum-of-two vanished while walking her dog Willow in St Michael’s on Wyre in Lancashire, on the morning of January 27.
Faulding, who assisted police in a river search along with a team of divers, is now also scouring where she could be on land.
He now said he's planning on looking at possible 'deposition sites'.
He has also now compiled a list of areas “where it would be possible to secrete a body without anyone noticing”.
Faulding added: "Normally poeple aren't found too far away, often within a couple of miles," according to The Sun.
Yesterday, police started searching a caravan site near to the river where her found was found on a bench and Willow's harness on the floor.
The caravan site being visited by officers is believed to be one of several CCTV 'blind spots' identified in the search for Ms Bulley.
A friend, named Tilly-Ann, previously wrote in a Facebook post backed by Ms Bulley's family: "There's CCTV at the back of the caravan park.
"The only camera that isn't working is the one that would have seen everything."
It comes as police officers are reportedly widening their investigation to include the day before she went missing.
As part of their investigation, detectives are claimed to have now requested CCTV footage from a local garage that covers one of the exit points from the field where she vanished.
Meanwhile, a witness has reportedly told police that he spotted two men acting suspiciously close to Nicola's dog-walk route the day before she went missing.
The allegedly suspicious pair were seen outside a local church on January 26, according to reports.
It is unclear if the police reportedly collecting CCTV on the same day is connected to these claims.
A worker at St Michael's Garage told The Sun on Sunday: "Two smartly dressed officers came in following up, a man and a woman.
"They wanted the CCTV from the day before Nicola vanished and to take statements of any activity we had seen from that day.
"These officers were different to the ones in uniform, they seemed very assertive."
