Last seen in her crib, Lisa Irwin,10 months old, has gone missing since Monday.

Her mother, Deborah Bradley, was the last person to have seen Lisa in her crib and 5 hours later when Lisa's father, Jeremy Irwin, came home after a late night shift at work, he did'nt find her.

After a five-day thorough search in and around the city, the officers are still clueless about the baby's whereabouts, and the latest and probably the only development in the investigation so far is that Bradley has apparently failed a polygraph test.

Officers have already done much of the investigation, looking for the baby in the city using helicopters, searching all-terrain vehicles and conducting door-to-door interviews, all in vain.

Bradley and Irwin, Lisa's parents, appeared on National News shows on Friday morning, revealing the couple's plight at the disappearance of their 10-month-old daughter. They expressed their disappointment over the investigation tactics of a few investigators.

 On the Today show, Bradley told the public that police had informed her that she failed a polygraph test.

I continued to say 'That's not possible,'  Bradley said. Because I don't know where she's at.

I did not do this.

She said the same things on Good Morning America.

From the start, when they've questioned me, once I couldn't fill in gaps, it turned into 'You did it, you did it,'  Bradley said.

They took a picture down from the table and said 'Look at your baby.' And 'Do what's right for her.' I kept saying 'I don't know...' I just sat there.

She said that she cooperated and answered all questions and did'nt even ask to leave.

The missing baby girl has blue eyes, blonde hair, is 30 inches tall and weighs around 28 pounds. The clothes in which she was last seen are purple shorts and a purple shirt with pictures of white kittens on it.

Lisa's parents on Wednesday tearfully begged to whoever has taken the baby to leave her somewhere safe. Please drop her off anywhere, her father, Irwin, had said calmly during a brief news conference at a makeshift police command center near their home. We don't care. Somewhere safe so she can come home.

Also till Wednesday, officials said that the parents were very cooperative in the investigation process.

Only on Thursday, did the Kansas City police say that the parents were no longer cooperating with investigators, and later in the night, an aunt of the missing child delivered a brief statement saying that the parents were, in fact, continuing to assist the authorities, the report said.

Irwin said Friday morning that this could be an overreaction from police to his request for a break during the previous day's questioning.

He had told them that he needed a break from the questioning sessions and that he wanted to go, he did not want to take anymore questions for that day. They saw the police press conference an hour later.

The police said that their main focus at the moment is to search for the baby, and that they will continue the search despite the parents' decision to stop talking with the cops.

Both parents have denied any involvement in their daughter's disappearance.

We continue to ask, answer all the questions the best we can and do everything they tell us to do and so, I mean, we've done everything we can do, Bradley told Good Morning America.

The police had issued an Amber Alert Tuesday morning but called it off after 12 hours. Police said it was a formality because the alerts are designed to raise awareness early in an investigation.