NICOLA Bulley could be living "off grid" and may never be found, a missing persons expert believes.
The mum-of-two, 45, was last seen in St Michael’s on Wyre, Lancashire, at around 9.15am on January 27.
But as the search enters its fourth week with no trace of the mortgage advisor - cops have been told to keep an open mind.
Police looking for the mortgage advisor say their main "working hypothesis" is that Nicola fell in the River Wyre.
But Charlie Hedges, who has worked with the National Crime Agency, believes there is "no indication" Nicola is in the river and stressed "we need to keep our minds open to all options".
He told GB News on Saturday "all lines of action" must be followed, adding: "It may be that she just took the decision to go off.
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"It's not that easy to go off the grid in today's world."
Lancashire Police faced heavy criticism for revealing Nicola had "significant issues with alcohol" as a result of menopause.
It also emerged officers had been called to the family's home after "a report of concern for welfare" on January 10, although a pal of Nicola's said there were "no red flags" in the run up to her disappearance.
Despite the disclosure - branded "deeply troubling" by some politicians - Charlie, who received an MBE for his work, stressed that such details are "really important".
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The ex-cop of 30 years explained: "I mean, nobody goes missing without a reason and understanding what's going on in someone's life is really, really important."
He did not rule out the importance of police searching the River Wyre.
But he pointed to the fact that the thorough search - which involved sonar and a range experts - yielded "no outcome".
There have so far been no sightings of the mum, from nearby Inskip, as the search for her enters its fourth week.
It comes as a police helicopter was spotted hovering above the River Wyre at Shard Bridge, in Hambleton, on Saturday afternoon.
The spot is around 7 miles from where Nicola went missing and is where the River Wyre widens before weaving its way to Morecambe Bay and out to the Irish Sea.
It is unclear what exactly the helicopter was doing but The Sun have approached Lancashire Police for comment.
Former cops also slammed "toxic" social media sleuths for involving themselves in the case.