The sister of a missing mother who went missing on a dog walk urges members of the public to "keep an open mind" and keep searching.

 Nicola Poley, 45, was last seen by the River Weir at St Michael's in Wey, Lancashire a week ago.

 On Friday, Lancashire Police said its officers believed she had fallen into the river.

 But Polly's sister, Louise Cunningham, said there was "absolutely no evidence" of this

 She added, "Everyone should keep an open mind as not all CCTV and leads have been fully investigated and the police confirmed that the case is not over yet."

 The search is still going on, including police divers, drones, a helicopter, and search and rescue teams, but no trace of her has been found.

 "The working hypothesis is that she fell into the river for some reason," the police said.

 Supt Sally Reilly said: "There is absolutely nothing to suggest from all our extensive investigations that anything untoward has happened to [Ms. Polly] or that there is any third party involvement in her disappearance."

 She said it was still a missing person investigation.

 Ms Polly was last seen walking her dog Willow near the River Wire after dropping off her children, aged six and nine, at school on the morning of January 27.

 The spaniel was found about 25 minutes after Bullie was last seen by another dog walker at around 09:10 GMT.

 Her phone was also found on a bench by the river - still connected to a business call.

 Emma White, one of Ms Polly's friends, who was helping with the search, said she thought "we actually didn't get any further than last Friday unfortunately".

 "We still don't have any evidence and that's why we're out strong again.

 "You don't build life on a hypothesis, do you? You can certainly make hypotheses but then you need something to support that hypothesis to become realistic."

 Investigators said they were "as confident as possible that Nicola did not leave the field where she was last seen and our working hypothesis is that for some reason she fell into the river".

 Our investigation remains open and we will of course work on any new information that comes to light.

 Polly's partner, Paul Ansell, said he would "never give up hope" of finding her.

 Police urged local residents to search along the river for the clothes Mrs. Polly was last seen wearing.

 This includes a black ankle-length gilet jacket, a black waist-length Engelbert Strauss coat, black jeans, green walking socks, a green ankle-length hoodie, a necklace, and a pale blue Fitbit.