Updated

The lawyer for Casey Anthony, mother of missing toddler Caylee Anthony, disclosed late Tuesday that the family had received a credible tip that a small child matching Caylee's description was seen boarding a flight to Atlanta at Orlando International Airport.

The tip was even more credible because the person reported that the little girl pronounced her last name the same way Caylee's grandparents say she does, attorney Jose Baez told FOX News.

The child's grandmother Cindy Anthony confirmed that the lead surfaced late Tuesday. She said the tip was from a woman who lives in Orlando and was left on her voicemail. Cindy Anthony said she called the woman back and they talked.

The caller claimed to have seen Caylee board the flight with an older woman. When she talked to the woman and child, the youngster apparently said her name was Caylee "Antony," pronouncing it without the "h" the way Cindy Anthony says her granddaughter does. When asked her age, the little girl said she was 3; Caylee is almost 3 years old.

Click for more from MyFOXOrlando.com.

Meanwhile, a judge set bond at half a million dollars for Casey Anthony Tuesday after detectives testified that she is a "person of interest" in the little girl's disappearance.

Anthony, 22, has been jailed since last week and was hoping to win release at a bond hearing in Orange County, Fla. The whopping $500,000 she needs to post will make it difficult for Anthony to get her wish.

Prosecutors said the case is beginning to look like a homicide.

Anthony's attorney said there is circumstantial evidence of a possible killing, but not enough to give prosecutors the confidence to charge her with homicide, kidnapping or any similar offense.

Detectives revealed that Anthony had become more of a focus of their investigation into her daughter Caylee's disappearance after they found evidence of human decomposition in the trunk of a car she drove.

• Click here for photos.

Detective Yuri Melich testified that strands of hair similar to those of Caylee Marie Anthony as well as dirt were found in the trunk of a car used by her mother.

The odor of "decomposition" was also detected in the vehicle, he told the judge presiding over Casey Anthony's bond hearing Tuesday afternoon.

"The smell I smelled was that of decomposition," Melich said.

When asked whether he considered the child's mother a suspect in her disappearance, Melich said he'd classify her as a "person of interest."

Melich also said a witness he interviewed remembered seeing bruises on Caylee's body and a mark under her eye without knowing that Melich had a photo showing similar marks on the toddler, who has been missing more than a month.

On cross examination, Melich admitted he didn't have any direct evidence that Casey Anthony played a part in her little girl's disappearance.

Investigators used cadaver dogs to search the child's grandparents' yard last week after a neighbor told them Anthony had asked to borrow a shovel around the time her daughter Caylee was last seen.

They have previously said that almost nothing Anthony has told them about her child's disappearance has checked out to be true. They haven't even been able to get information about the child's father, who Anthony has said is dead, Melich testified.

Also at Tuesday's hearing — held to argue over whether or not to release Casey from jail — the child's grandmother said her daughter is a good mom and hasn't committed a crime but has been dishonest before and has had trouble keeping jobs.

"Casey's lied to me in the past and when she's lied she's always told me the truth," Cindy Anthony said. "We've gotten to the bottom of the truth when I talk to her and spend time with her."

She told attorneys that her daughter is her "best friend outside my husband" and she had no reason to believe anything had happened to her granddaughter until last week because she'd "spoken to Casey on a daily basis."

"Without a doubt, she is a great mom," Cindy Anthony testified. "You can see it in her eyes. You can see it when they're together. There's nothing but love."

She said her daughter should be released from jail "because she hasn't committed a crime" and because she needs to help find Caylee.

Cindy Anthony speculated on the stand that someone was threatening her daughter and that's why she hasn't told the whole story about where Caylee is.

Earlier Tuesday, Cindy Anthony said Casey left the child in the care of someone she trusted, but that person betrayed her.

In an interview on FOX News Tuesday morning, she implied that her granddaughter might have been kidnapped.

Casey Anthony has been in prison since last week, when she finally reported her toddler daughter missing on Wednesday at her parents' urging.

Caylee was last seen June 9, according to Anthony — who investigators say has spun a Web of lies in their interviews with her. She was arrested on charges of child endangerment, making false officials statements and obstructing a criminal investigation.

Her attorney denies that his client has been lying to police and says she's been cooperating.

"My client at no time refused to speak with law enforcement," said lawyer Jose Baez at a Monday press conference. “We are focused on trying to find Caylee. We want to find Caylee.”

Anthony was denied bail at a hearing last week.

Cindy Anthony said her daughter "has her reasons why she just can't blurt out the whole story."

"Casey has been trying to tell the police in her own way what she can tell them and the only unfortunate thing is, you know, they want a clear picture," Cindy Anthony told FOX News on Monday. "There's no clear picture. Casey has her reasons why she just can't blurt out the whole story, so she's been honest with them for what she can be honest with."

Volunteers in the Orlando, Fla., were continuing to canvass neighborhoods this week, distributing about 50,000 fliers, according to MyFOX Orlando.

A local foundation and business owner were offering a new reward of a combined $125,000 for any information about Caylee's disappearance or whereabouts, MyFOX Orlando reported. The reward will be in effect for at least the next three months.

Orange County sheriff's detectives say they have few new leads. Authorities are looking into the family's claims that Casey Anthony received a mysterious call from her daughter last Tuesday.

Click here for photos of the bond hearing from MyFOXOrlando.com.

FOX News' Catherine Donaldson-Evans and The Associated Press contributed to this report.