A body has been found in a river close to where Nicola Bulley disappeared more than three weeks ago.
The body, which has not yet been formally identified, was found on Sunday morning about a mile from where the 45-year-old mortgage adviser was last seen along the River Wyre in Lancashire.
Bulley, from Inskip, Lancashire, was last seen walking her dog next to the River Wyre in the village of St Michael's on Wyre on 27 January, after taking her two daughters, aged six and nine, to school.
There have been three main theories surrounding her disappearance.
Lancashire Police said previously it is investigating all possible leads and "reviewing our decisions regularly".
The force has always maintained its “working hypothesis” was that Bulley fell into the river, saying it had found no evidence of any “criminal aspect or third party involvement”.
Here are the three main theories behind Bulley's disappearance.
Nicola Bulley fell into the river - theory #1
Lancashire Police's main theory about Bulley's disappearance has been that she fell into the River Wyre while walking her dog.
The 45-year-old's mobile phone was left on a bench still connected to a Microsoft Teams call and her spaniel Willow was found nearby without a harness.
Watch: Body found in river near where Nicola Bulley went missing
After an extensive search of the river in the days following her disapperance produced no results, search teams shifted their focus to the 10 miles or so of river downstream of the bench, where the River Wyre empties into the sea at Morecambe Bay.
Bulley's family and friends have continued to question the main theory, with her partner Paul Ansell saying he is "100% convinced it’s not the river."
Detective Superintendent Smith has maintained her “main working hypothesis” is that Bulley fell into the River Wyre.
At a press conference at Lancashire Police HQ last week, she said: "At the initial stages based on the information I received, I made it clear that it was my working hypothesis at that time based with all the facts that the main hypothesis I was working on at that time was that Nicola had gone in the river.
“This has been misconstrued in the press and said that that was what I said. I said that was my main working hypothesis at that time, and that remains my main working hypothesis.”
Diving and forensics expert Peter Faulding, whose team searched a section of the river, has previously said he doesn't believe Bulley fell into the river after failing to find her.
He had described her disappearance as a mystery, and said if was in the river then she would have needed to have been "shoved really hard".
Tilly Ann, a friend of Bulley, also disputed the idea she had gone into the river, saying she was "an incredibly strong swimmer".
Third party involved - theory #2
Former detective Mark Williams-Thomas said last week that "foul play" could be an option.
He tweeted: "For me the three options still remain very much on the table in relation to Nicola Bulley disappearance - all have some credence - although 1 and 2 are looking far less likely now. 1) She went into the water by some means 2) She left of her own accord 3) Foul play 3rd party."
But assistant chief constable Peter Lawson said that while Lancashire Police remain “open-minded”, there is still “no evidence to indicate a criminal aspect or third party involvement”.
He said: “I would emphasise that it remains the case there is no evidence to indicate a criminal aspect or third party involvement in Nicola’s disappearance.
“However, the officers involved in the investigation are the same experienced specialists and many senior officers who are concerned with the investigation of the most serious and complex crimes.”
Faulding has previously suggested that a third party could be involved, and speculated that Bulley's phone could have been placed on the bench as a "decoy".
Nicola left area of her own accord - theory #3
At one point in the search last week, police said they were also looking at whether Bulley "could have left the area voluntarily".
Officers combed through hundreds of hours of CCTV and dashcam footage, without finding any evidence Bulley left the area.
Police have given no update about this theory.
Watch: Family and friends question police theory that Nicola Bulley fell in river