Police have requested the help of a dog whisperer and behavioural profiler in the search for missing mum-of-two Nicola Bulley, it is reported.
The 45-year-old was last seen over three weeks ago, at 9.10am on January 27, while walking her springer spaniel Willow in St Michael's on Wyre, Lancashire.
Her phone, still connected to a work call for her job as a mortgage adviser, was found just over 20 minutes later on a bench overlooking the riverbank, with her dog wandering loose while "bone dry" and "agitated".
The force has so far failed to solve Ms Bulley's mysterious disappearance, previously saying that its main working hypothesis is that she fell into the River Wyre in a "10-minute window".
It has also recently come under fire for making Ms Bulley's struggles with alcohol and the menopause public, and has set a date for an internal review into their investigation.
As pressure mounts on the force, it has reportedly drafted in a behavioural profiling expert and a forensic clinical psychologist.
Police have also made contact with a dog behavioural specialist to collect any information from Ms Bulley's springer spaniel, reports the Sunday Times.
It has further drafted in the help of a detective who worked on the case of murdered police community support officer Julia James, according to the paper.
The move comes as Ms Bulley's father Ernie Bulley says "every day is a struggle" since his daughter vanished.
He told Sky News on Friday: "[We're] no further on from three weeks ago. [We] just need a breakthrough to give us some hope."
In a press conference on Wednesday, Lancashire Police revealed Ms Bulley was classed as a "high-risk" missing person immediately after her partner reported her disappearance "based on a number of specific vulnerabilities".
They later added in a statement that she had been struggling with alcohol issues and the menopause, and had stopped taking HRT medication.
Information Commissioner John Edwards has said he will be asking the force about its decision to make the information public, adding: "Data protection law exists to ensure people's personal information is used properly and fairly. This includes ensuring personal details are not disclosed inappropriately."
Former victims' commissioner Dame Vera Baird said she believed the force had made a "dreadful error" in releasing the details.
And Rishi Sunak said he was "concerned that private information was put into the public domain", telling broadcasters: "I'm pleased that the police are looking at how that happened in the investigation.
"Obviously my thoughts are with Nicola's friends and family and the focus must now be on continuing to try and find her."
A source close to the Home Secretary said Suella Braverman had also outlined her concerns over the disclosure during a meeting with Chief Constable Chris Rowley and his senior team on Friday, and "asked to be kept updated on the investigation".
A Lancashire Police spokeswoman said: "A review of the investigation is diarised and will be conducted by our Head of Crime Detective Chief Superintendent Pauline Stables."
Ms Bulley's family have called for a stop to "speculation and rumour", adding: "The public focus has to be on finding her and not making up wild theories about her personal life."
The search for the missing mum has been extended to the sea, but she has not been found.