Lancashire Police have issued an appeal for drivers and cyclists that used a river path on the morning that mother-of-two Nicola Bulley went missing to come forward.
It comes as Paul Ansell, the partner of the 45-year-old, said that the couple's children "miss their mummy desparately" and "need her back".
Detectives say that although the 'working hypothesis remains' that Ms Bulley fell into the river in St Michael's on Wyre they are continuing to carry out a number of different enquiries.
In a statement a spokesperson for Lancashire Police said: "Our enquiries now focus on the river path which leads from the fields back to Garstang Road – for that we need drivers and cyclists who travelled that way on the morning of 27 January to make contact."
"Nicola was last seen on Friday morning at around 9.20am on the upper field by the river off Garstang Road where she had taken her Spaniel Willow for a walk after dropping her children at school in the village.
"We will be making contact with drivers, who we believe were travelling down Garstang Road that morning via letter. If you receive one of these letters and have dashcam footage, we would urge you to make contact using the dedicated email NicolaBulleyInvestigation@lancashire.police.uk so that a member of the enquiry team can make contact and review your footage to establish whether it assists. We would ask that only drivers that do have dashcam footage reply to this request."
In a statement, also released via the police, Nicola's partner said "It's been 10 days now since Nicola went missing and I have two little girls who miss their mummy desperately and who need her back.
"This has been such a tough time for the girls especially but also for me and all of Nicola's family and friends, as well as the wider community and I want to thank them for their love and support."
Later on Monday night, the head of a team of private underwater search experts cast doubt on the force's current working hypothesis that Ms Bulley had fallen into the river.
Ahead of the Specialist Group International (SGI) beginning its second day of searching the River Wyre on Tuesday, Peter Faulding said he did not think the missing mother was in the water.
After spending Monday searching "three or four miles" of the river until it grew dark alongside Lancashire Police, Mr Faulding told the PA news agency: "It's a negative search, no signs of Nicola".
He added that his team will look through another stretch of river on Tuesday "towards where Nicola went originally missing".
Mr Ansell, her partner, meanwhile said in his statement: "This has been such a tough time for the girls especially but also for me and all of Nicola's family and friends, as well as the wider community and I want to thank them for their love and support.
"We are also really grateful to Peter and his team from SGI for coming up and helping support the work of Lancashire Police as they continue their investigation."
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