Those searching for missing mum Nicola Bulley have been told of a critical ‘blind spot’ after another appeal for evidence.
Friend Jill Peck has highlighted a “missing” section of road in the investigation into her disappearance.
She has called for calling for anyone with dash-cam footage to come forward as they “just need answers”.
The 45-year-old vanished on a dog walk in St Michaels on Wyre on January 27.
Her phone was found on a bench overlooking the water and major search effort was launched.
Detectives maintain their “working hypothesis” is that Ms Bulley fell into the river as the leader of a specialist investigation team said his “gut instinct” was that there was a “third party” involved.
Police have drafted in independent underwater forensic experts Specialist Group International this week as the hunt continues.
Now, close friend Ms Peck has launched a further appeal as she desperately awaits news.
She told GB News: “We just need some answers, we need factual facts, we need evidence. Anyone out there that feels they may have dashcam footage, there's a section of road that we're missing, Garstang Road towards St Michaels.
"We just need some answers,” she added.
Police had earlier identified a key ten-minute gap in their knowledge of Ms Bulley’s movements on the day she vanished.
The gap is between 9.10am when she was last seen, and 9.20am, which is when police believe her phone was placed on the bench where it was later found.
Another of her friends, Heather Gibbons, said "nothing is making sense" in the case as she said speculation on social media is hurtful to the family.
She told the BBC : "I know that the family are massively appreciative of all the police have done [and] we feel we have got the best of the best on that water.
"Hopefully it will be a completion, one way or the other, and if they find nothing, then maybe it's time to start looking down other avenues.
"Up to a certain level, we understand it's human nature, it's natural for everyone to have speculation, because the truth is in this, nothing is making sense."
Firm chief Peter Faulding previously told the Mirror his team's sonar could find Nicola in under an hour if she is in the river - however, he expressed doubts she ever fell in.
He added that he considered it almost impossible that she would have been dragged down to the estuary, hypothesising that a body would become "snagged" within 500 metres of the entry point.
His team yesterday trawled what they consider the "hot zone", as well several miles up and downstream, but neither they nor police specialists found any evidence of Nicola.
Lancashire Police Superintendent Sally Riley told a press briefing on Tuesday the force continued to rule out any "suspicious or criminal" element to the case.
She said a team of 40 detectives are working on around 500 different lines of inquiry and are identifying more than 700 drivers who travelled through the village around the time Nicola disappeared.
She said: "This is normal in a missing person inquiry and does not indicate that there is any suspicious element to this story.
"The inquiry team remains fully open-minded to any information that may indicate where Nicola is or what happened to her."
But the police chief emphasised that detectives have not yet come across any evidence of foul play.
"Any criminal or suspicious element has been discarded," she said.
"It is important to stress that any information that comes in that indicates otherwise is being checked out all the time.
"We are not closed in any way to any particular line of inquiry but all these extensive inquiries, however, have so far found anything of note."
