Photos of missing mum Nicola Bulley's dog Willow swimming could undermine a key police theory.
The 45-year-old mum disappeared while out walking her springer spaniel along the River Wyre in the village of St Michaels, Lancashire, on January 27.
Her phone was found on a bench overlooking the water, with the dog wandering alone nearby.
A major police search was quickly launched before it was confirmed the force's main hypothesis was Nicola accidentally fell into the water.
Superintendent Sally Riley said there was a chance the missing mortgage adviser had gone to the water's edge due to something relating to Willow.
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She suggested perhaps the dog had dropped its tennis ball into the river - with the spaniel having been completely dry when she was found.
However, Nicola had shared a number of photos showing Willow happily swimming in open water on the same route.
The images posted on social media by Nicola last year seem to imply the dog was comfortable around water and its owner likely wouldn't have been overly concerned.
In one image, Willow is seen with the ball in her mouth, swimming happily towards Nicola.
That was snapped on July 5, 2022, and was captioned: “A quick morning walk before a busy day ahead!
“Willow living her best life!”
This set of photos was tagged as being taken in St Michaels on Wyre, where she would go missing seven months later.
Another image taken in April 2022, shows a very wet Willow standing on the sandbank next to the river having clearly just been chasing the ball into the water.
Another image from that set shows Willow moments before she went into the water.
"And therefore whilst I don’t want to speculate as to what may have happened, it is our working hypothesis that she has entered the water accidentally and that’s why there is no physical evidence on the field," said Supt Riley.
She went on to say: "The dog was off the lead, this was normal for the dog to run about and Nicola was on a teams call, which again it would be normal for her not to participate in actively and just have the phone to listen in, effectively.
"Anything could have happened with the dog whereby Nicola may have gone - and I don’t wish to speculate, we don’t know - but it is possible the dog was loose and off the lead that there may have been an issue with the dog that led her to go near to the water’s edge.
"She puts the phone down momentarily and Nicola may have fallen in. That is a possibility," said Supt Riley.
She confirmed the dog was dry when found by other walkers.
"We don’t believe the dog was in the river because the dog, we believe, was dry and the witnesses have not described the dog swimming or jumping into the river.
"We don’t know why Nicola may have entered the water if she did," she added.
Lancashire Police did not wish to comment on the matter when approached by the Mirror.