A witness has told police he spotted two men acting suspiciously close to Nicola Bulley’s dog-walk route the day before she went missing.
Detectives have also taken CCTV footage from a garage covering the 24 hours before the mum-of-two's last sighting.
The 45-year-old vanished on January 27 after taking springer spaniel Willow onto a river towpath in St Michaels on Wyre.
Lancashire Police had previously ruled out foul play and believe she likely fell into the the River Wyre near a bench where her phone was found.
However, they currently don't have any evidence to back up the hypothesis with weeks of trawling the river and surrounding area providing nothing substantial.
The allegedly suspicious pair were seen outside a local church, according to reports.
The same witness is said to have told officers he saw one of the men in the area of Nicola's usual route on the morning she disappeared.
An employee of the garage where police took the latest CCTV told the Sun plain clothes detectives arrived asking for the footage from the day before the disappearance.
“These officers were different to the ones in uniform, they seemed very assertive,” he said.
They said of the sighting: “I know who the witness is and he has already called police about what he saw.
"But he said he wanted to make sure they were chasing this up so I asked the officers about it and they said they were following it up.”
He went on to say the witness saw the men close to the church and around a nearby bridge on January 26.
It is unclear if the police collecting CCTV from the same day is connected.
With the search entering its 17th day, those in charge of the investigation have begun to widen their search.
After independent underwater forensics experts from Specialist Group International (SGI) completed their search of the river, police were seen trawling in the estuary and Morecambe Bay.
