Police continue to search for a couple and their dog who went missing from a California nudist community, telling reporters Thursday that foul play is now suspected in their disappearance.
Stephanie Menard and Daniel Menard were reported missing on Sunday, according to the Redlands Police Department.
During a press briefing on Thursday, the Redlands Police Department said foul play is suspected after being tipped off by a source in the couple's neighborhood.
The Menard's next-door neighbor is being investigated as an alleged person of interest, police said.
Officials said they are conducting a remote search of the neighbor's property and have the area locked down during the investigation.
The location and condition of the Menards and their dog remains unknown, police said.
The couple were last seen at their residence on Olive Dell Ranch -- a family nudist resort -- at around 10 a.m. PT on Saturday. Their unlocked vehicle was found down the road from the residence that day, according to police.
MORE: Dog breeder found dead and as many as 10 of his Doberman puppies have vanishedStephanie Menard's purse was found inside their residence along with both of their cellphones, according to police.
The couple's dog, a white Shih Tzu named Cuddles, was also missing.
"There's no way that Stephanie or Dan could have walked away from that car," friend Tammie Wilkerson told Los Angeles ABC station KABC. "She has a cane. It was at home, her purse, their cellphones -- things they would never have left at home."
She added, "They're very sweet people. There's not a mean bone in their body at all."
Daniel Menard also has dementia and is diabetic, according to police.