Updated

Maine police released new images Monday as they continue asking for the public to come forward with any details or possible sightings of a missing mom, her ex and their 2-year-old daughter, who vanished almost three weeks ago.

Jill Sidebotham, 28, Nicholas Hansen, 38, and their toddler Lydia set off on June 27 for what was supposed to be a three-day camping trip. Newly released surveillance images show the clothes they were wearing on June 29 at the campground.

They never returned home.

Police have confirmed two sightings, on June 29 and July 2, the latter at a Walmart store in Mexico, Maine, about 100 miles from Sidebotham’s home in Sanford.

MAINE PARENTS AND TODDLER MISSING AFTER CAMPING TRIP

Jill Sidebotham enters a store behind Nicholas Hansen, who is carrying little Lydia

Jille Sidebotham, Nicholas Hansen and their daughter Lydia seen on surveillance video at the Coos Canyon Campground on June 29. (Sanford Police Department)

Detectives visited Mexico to investigate some leads Friday, Sanford Police Lt. Matthew Gagne told Fox News Digital. Store clerks who encountered the parents and child reported nothing unusual and no signs of distress.

Despite reports that Hansen may have been abusive, police have no evidence that Sidebotham was in distress and say she went on the trip voluntarily. Hansen’s state criminal records contained no violent convictions.

"We don't have any evidence to believe that this is a kidnapping or some sort of abduction," Gagne said. 

Newly released images show the three entering a store at the Coos Canyon Campground on June 29. In different screengrabs from surveillance video, both parents can be seen carrying Lydia. Sidebotham is wearing a black T-shirt and light-colored shorts. Hansen is wearing a red T-shirt with the sleeves cut off. He has a short beard and a bald patch on the back of his head. 

Lydia was wearing red.

Jill Sidebotham holds her daughter Lydia Hansen in her lap

Jill Sidebotham, 28, and her 2-year-old daughter Lydia Hansen were last seen on July 2 at a Walmart store in the town of Mexico, Maine. (Sanford Police)

Police are hoping that they can learn more if more witnesses come forward with potential sightings.

The Maine Warden Service led two aerial searches around Mexico and Rangeley last week looking for the car the missing group was believed to be traveling in: a silver 2005 Volkswagen Jetta, with a black rear bumper and Maine license plate 1563VJ. They found nothing.

"The vehicle has not been seen at all," Gagne said. "We don't even have a photo of it."

Because of the large distances involved, anyone who sees Sidebotham, Hansen or Lydia is asked to contact local law enforcement.

UNIVERSITY OF MISSISSIPPI STUDENT JIMMIE ‘JAY’ LEE NOW MISSING FOR A WEEK AS FATHER APPEALS FOR TIPS

Nicholas Hansen poses in front of a brick wall

Nicholas Hansen, 38, has not been seen since July 2. (Sanford Police)

Sidebotham’s family told the Boston Globe earlier this month that Hansen, her ex-boyfriend, asked her to go on an impromptu trip on June 27.

MISSING DYLAN ROUNDS: UTAH DEPUTIES NAME SQUATTER NEIGHBOR AS SUSPECT IN DISAPPEARANCE OF 19-YEAR-OLD FARMER

Jill Sidebotham lives in Sanford with her parents, who had advised her not to accept Hansen’s invitation to go camping, the elder Sidebotham, who did not respond to Fox News Digital’s inquiry, told several media outlets. Her Facebook account indicates that she has a 10-year-old son from another father, and she is reportedly engaged to another man.

Sidebotham’s fiancé, Corey Alexander, 31, told The Sun that he fears something has gone "very wrong."

CLICK HERE TO GET THE FOX NEWS APP

"She was always upfront with me about everything," he told the outlet. "We never hid anything from each other. She never mentioned anything about the camping trip to me."

He said he last heard from her on June 29 over Facebook Messenger.