Police have been given the power to break up groups interfering with the search for Nicola Bulley in St Michael's on Wyre, after reports of amateur sleuths filming properties and uploading them on social media.
The dispersal order has been granted as the focus of the major search for the missing mother-of-two shifted towards the sea.
Lancashire Police said the powers were issued on Wednesday night after reports that people had come to the village from outside the county to film.
Attempts are believed to have been made by a group to search an abandoned house, before being stopped by police, with it also being revealed that the property had already been fully investigated.
The order will remain in place for 48 hours and gives officers the ability to disperse anyone committing anti-social behaviour.
Police said two dispersal notices were issued and a number of other people were warned about their behaviour as the force warned it will not tolerate criminality, including trespass and criminal damage.
Officers had previously warned members of the public not to "take the law into their own hands" by breaking into empty or derelict riverside properties to try to find Ms Bulley.
Lancashire Police also said it was looking into a number of "grossly offensive" comments being made on social media and may take legal action "where appropriate".
Ms Bulley's disappearance has prompted lurid comment on social media and a steady stream of individuals have appeared in the village, often filming police activity around the area where she disappeared.
Meanwhile, police search teams were on Thursday spotted on the River Wyre, miles from where Ms Bulley first went missing 14 days ago.
A dinghy with two officers on board could be seen on the water, as the focus of the massive search shifted from where she vanished to farther downstream, towards where the River Wyre empties into the Irish Sea at Morecambe Bay.
An orange rescue boat was also spotted appearing to do sweeps of the river off Knott End-on-Sea, at the mouth of the bay, about 10 miles downstream from where the 45-year-old vanished on January 27.
The mortgage adviser had dropped off her daughters, aged six and nine, at school, then took Willow, her springer spaniel, for a walk alongside the River Wyre.
Police believe she fell in the river while on the walk, leaving her phone on a bench, still connected to a work call.
Lancashire Police dismissed any suggestion Ms Bulley was a victim of crime, and said the scale of the missing person inquiry is "unprecedented", involving 40 detectives and following 500 lines of inquiry.
Multiple searches of the "hotspot" area near the bench, the suspected "entry point" of where Ms Bulley went into the water, have been conducted by police divers and underwater search experts.
Ms Bulley's family called in help from Peter Faulding, of Specialist Group International, but after a three-day search earlier this week, no trace of her was found.
Mr Faulding said his searches confirmed Ms Bulley was not in the section of river searched by his team and police divers, but described himself as "baffled" after ending his fruitless search.
Police said that though its presence around where Ms Bulley disappeared would be less visible on Thursday, it didn't mean there was a scaling back of the search, but a shift in focus to further downstream in the area of the river where it becomes tidal and out towards the sea.
Ms Bulley's partner Paul Ansell has described the "perpetual hell" the family is suffering as they await news, with her daughters asking: "Where's Mummy?"
