An "old abandoned" house has been searched in a bid to locate missing dog walker Nicola Bulley.

Teams scoured the area near Garstang Road in St Michael’s on Wyre in Lancashire as they tried to trace the 45-year-old.

She was last seen on Friday morning at 9.15am as she walked along a footpath to a river.

The mother-of-two's phone was found still logged on to a conference call from a bench where she had been out walking her pet dog Willow.

It is said she had her camera off and the call was muted.

She had dropped off her two young children at St Michael's-on-Wyre Church of England Primary School before heading on a walk. 

Kev Camplin, of Bowland Pennine Mountain Rescue, said the grounds of a large unoccupied country house, along with a long stretch of the river, including wooded areas and water margins were searched.

He said: "The abandoned house is right opposite the bench on the other side of the river, over a 10ft garden wall. It’s quite posh.

"We didn’t go into the house, as a volunteer search and rescue team we don’t actually go into buildings. We might go into a barn or something.

"We leave that to the police. While the team was searching the grounds, the owner was there for some reason, and we asked him to go in and he had a quick look around and she wasn’t there."

He led a search team of 25 volunteers, who were kitted out with mountain rescue radios and were led by an operator inside a control van with mapping systems.

"We probably searched a mile north upstream and then we probably searched probably three miles downstream," he added. "We covered quite a bit."

Mortgage advisor Ms Bulley lives in Inskip, around three miles away from where she went missing. Mr Camplin said it was an area she was familiar with.

"She drops her kids off at St Michaels and then apparently she walks eastwards to where the woods and the river are, she walks that daily with her dog," he said.

"So it’s not an unknown area for her, and it is a popular area for walkers and dog walkers alike. It’s actually quite a beautiful spot.

"Leaving the phone on the bench and then disappearing it is quite odd. We don’t normally get that.

"Sometimes we go to a search, classed as lowland search. You do get a car… where somebody has left their car. That’s the initial planning point.

"But her car was at the school and her phone was the initial planning point. Later we find out she was on a team's work call. We didn’t know that on Friday. I knew the phone was there, but not on a work call."

Police on Tuesday night said they were speaking to a "potentially key" witness, who was in the area at the time she disappeared. 

The force is treating the case as a missing person's investigation.