Isabel Celis
Police haven’t revealed what it is, but a clue towards the whereabouts of a missing Arizona girl was found by FBI dogs on Monday. Facebook

Police from Tucson, Ariz., who are investigating the disappearance of 6-year-old Isabel Celis, have released 911 tapes from the day her parents called the emergency number after finding their daughter missing.

The search for Isabel Celis began when she was first reported missing on April 21, from her home in Tucson, Ariz. The high-profile case has attracted the attention of people across the country as Tucson Police, the FBI, the U.S. Marshalls and Mexican authorities search for the 6-year-old.

In the audio recording, Isabel's father, Sergio Celis, calmly talks to the 911 operator before being transferred to police.

I want to repot a missing person, said Sergio Cellis, Isabel's father on Saturday, April 21, reported ABC. My little girl, who is 6 years old. I believe she was abducted from our house.

The operator then asks Celis why he thinks his daughter was taken.

I have no idea, he said, reported Reuters. We woke up this morning...and she's gone. I woke up my sons, I, we looked everywhere in the house, and my oldest son noticed that her window was wide open and the screen was laying in the backyard. We've looked all around the house.

The operator then asks where the mother is. Celis said that she went to work, but he informed her of the situation.

I just called her to get her butt home, he said with a laugh.

Another emergency phone call was placed by Isabel's 14-year-ol brother, Sergio, who gives the phone to his mother Rebecca. Both are frantic and worrisome on the phone.

I went to work at seven this morning ... and she is five, six, could you please hurry and get someone over here, she said, as she begins to cry.

However, Rebecca begins to compose herself when the emergency operator asks for specific information regarding her missing daughter, reported ABC.

At a press conference on Monday, Tucson police discussed the decision to prevent Sergio Celis from having contact with his two sons, who are 10 and 14. While they did decline to provide any relevant information for the decision, they said it should not be an interpretation that he is a suspect in the case.

A voluntary agreement was reached between Child Protective Services and the parents to restrict access or, voluntarily, for Sergio to give some space and distance away from the two older children, Tucson Police Chief Roberto Villasenor said.

Police said they developed new information regarding the welfare of the children.

This does not mean we have settled on a path in this investigation, the chief said, reported the Daily Beast.

However, police did not specifically say they ruled out the parents as suspects. Police said they are looking at many scenarios regarding the incident. Villasenor conceded that their relationship with the family is somewhat more strained because the family members have not been ruled out as suspects.

We are doing more interviews and are asking more pointed questions, he added, reported the Daily Beast.

Since she has been missing, police have received thousands of tips and estimate they spent almost $1 million searching for Isabel. Isabel's parents have made several public claims, hoping she would return safe.

Every day makes us a little more worried, Villasenor said, but I'm not going to give up hope.