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The search for a missing Tennessee toddler has shifted to the northwest corner of North Carolina as authorities grow increasingly frustrated in their desperate bid to find the little girl, officials said Wednesday.

The mother and grandmother of 15-month-old Evelyn Mae Boswell have both been arrested — and put in the same jail — as deputies in two states continue looking for her, Tennessee's Sullivan County Sheriff Jeff Cassidy said.

"They are actively looking in an area in Wilkes County North Carolina" for the girl, Cassidy told reporters.

Megan Boswell SCSO

A representative for the Wilkes County Sheriff's Office could not immediately be reached for comment on Wednesday afternoon.

The child, Evelyn Mae Boswell, was last seen in December but was reported missing only this month, authorities have said.

The girl's mother, Megan Boswell, 18, has been charged with one count of false reports by the Sullivan County Sheriff's Office and is being held in lieu of $25,000 bail, officials said.

A visibly frustrated Cassidy said Wednesday that the young mother has hindered the search.

"Every time we talk to her, her story changes," Cassidy said. "I’m serious when I say that. Every single time."

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During the course of the investigation, Boswell provided investigators with a number of conflicting statements, the sheriff's office said in a statement.

"Further investigation revealed that some of the information provided by Megan Boswell was false," the statement said.

Questions have been raised about when Evelyn was last seen and reported missing, and state investigators say that people connected to the girl have given conflicting dates.

On Feb. 18, the sheriff's office got a referral from child services after the toddler's grandfather said Evelyn had not been seen for two months, Cassidy has said, and an investigation was launched.

The Tennessee Bureau of Investigation says that the date investigators have of when the girl was last seen was Dec. 26, but "the child's mother, along with others connected to the child, has given conflicting dates."

It was not immediately clear if Boswell has an attorney who could speak on her behalf. The jail said she was still being held late Tuesday.

Before she was arrested, Megan Boswell on Tuesday told NBC affiliate WCYB of nearby Bristol, Virginia, that her mother, Angela Boswell, was to babysit Evelyn.

"If you talk to anybody who actually knows me, they know that I would never hurt Evelyn or do anything like that," Megan Boswell told the station. She said that she misses her child and that the pain "just gets worse every day."

She also said the girl's father, who the sheriff has said is in the military and stationed in Louisiana, was trying to get leave to help look for the girl.

A statewide Amber Alert was issued Feb. 19, the Tennessee Bureau of Investigation said. The next day, in a search for clues, authorities asked for help finding a gray BMW in connection to the case.

The child's grandmother Angela Boswell and her boyfriend, William McCloud, were arrested in Wilkes County, North Carolina, in that 2007 BMW after its owner reported it stolen, WCYB has reported.

After their North Carolina arrest, McCloud told a judge that they did not know the car had not been paid for and that it was given to them by Megan Boswell, according to the station. Megan Boswell told WCYB on Tuesday that she did not want to comment on that claim.

Angela Boswell and McCloud were booked into custody on fugitive warrants unrelated to the toddler's disappearance. Angela Boswell was returned to the Sullivan County jail on Monday evening and arraigned on Tuesday on a theft charge, news outlets reported.

The little girl's mom, Megan Boswell, was put in the same Tennessee jail Tuesday night, and her bond was set at $25,000, the sheriff's office said.

The Tennessee Bureau of Investigation describes the case as complicated, in part because of the conflicting statements and the fact the child wasn't reported missing right away.

"We know you have a lot of questions about this case. So do we," agency spokesman Josh DeVine said in a video that was distributed on social media this week.

Authorities are looking for any information that could lead to Evelyn's whereabouts. More than 500 tips have been received, and agents and detectives are continuing to pursue any leads, the agency said.