Parents of Missing N.C. Girl Madalina Cojocari 'Not Telling Us Everything They Know': Police

North Carolina authorities continue to search for missing 11-year-old Madalina Cojocari while her mother and stepfather remain in jail.

On Tuesday, Cornelius Police Department Capt. Jennifer Thompson spoke about the case in a video posted to Facebook.

"Over the past 12 days, the Cornelius Police Department has led a massive investigation to find 11-year-old Madalina Cojocari," Thompson said. "One of the challenges in this case, simply put, we were not notified she was gone, a delay of three weeks."

Madalina, who disappeared on the night of Nov. 23, was reported missing on Dec. 15 by her mother.

Madalina's parents — 37-year-old mother Diana Cojocari and her stepfather Christopher Palmiter, 60 — were arrested on Dec. 17 after police say it took them three weeks to report the child missing.

Cojocari told police she held off on reporting her daughter missing because she "believed her husband put her family in danger," according to an arrest sheet reviewed by WBTV.com.

The girl's absence from the classroom prompted officials to reach out to the parents on multiple occasions.

"This is a serious case of a child whose parents clearly are not telling us everything they know," Thompson said. "Please call us if you have eyewitness information."

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Thompson said hundreds of agents, detectives and analysts have been involved in the investigation into Madalina's disappearance.

"Investigators have developed and followed nearly 250 leads spanning across state lines and across the globe," Thompson said. "We have interviewed hundreds of people in North Carolina and other states and again, across the globe."

Officers have canvassed the community and have gone door-to-door to at least 245 homes, Thompson said.

"We canvassed businesses and scoured through hours of surveillance video from all over the area. We also led land and water searches around Lake Cornelius as a precautionary measure," Thompson said. "Investigators obtained multiple search warrants for Madalina's home to make sure we legally gathered each and every possible piece of evidence to find Madalina."

The little girl was last seen as she was getting off her bus on Nov. 21, two days before she vanished. Police released surveillance footage of her exiting the school bus.

Madalina loved horses, and her extended family describes the sixth grader as a "beautiful, smart, kind and loving 11 year old girl with greatness in her future," according to a handwritten letter posted to the Cornelius Police Department's Facebook page.

"We are desperate to find her right now, she needs ALL of our help," according to the letter purportedly from the missing girl's extended family.

Anyone with information on her whereabouts or who has eyewitness testimony is asked to call the Cornelius Police Department at 704-892-7773 or 1-800-Call FBI.

According to the Cornelius Police Department, Cojocari and Palmiter have been charged with failure to report the disappearance of a child to law enforcement.

It is unclear if Cojocari and Palmiter have entered a plea to the charges against them, or retained attorneys to comment on their behalf.