The family of an Orlando toddler missing for more than a month won't answer questions about a tip that a new concrete slab was poured in the grandparents' backyard over July 4 weekend, shortly before they reported the child missing.
Caylee Marie Anthony's grandmother would neither confirm nor deny the tip about the fresh concrete received by local WFTV Eyewitness News in Orlando, according to the station.
Orange County Sheriff's detectives said they didn't know anything about the reported addition to the property, which they searched last week with cadaver dogs. The toddler was reported missing last week.
"We do yard work around our house all the time and our yard has been completely looked at," Cindy Anthony told WFTV Thursday morning. "I feel very confident. The sheriff's office knows everything that we've done in that yard over the last year. We've disclosed everything. If they had any concerns, I would think they would have followed up on it already."
Orange County, Fla., sheriff's detectives told FOX News they weren't aware of a recently-poured block of concrete.
Also Thursday, Cindy Anthony said there have been two reported sightings of 2-year-old Caylee in Georgia and she believes her granddaughter is with someone heading to Charlotte, N.C.
"We know where she's at," Cindy Anthony told FOX News Thursday before pleading with the person she believes has the child to turn back. "Please don't take her further into the mountains. It looks like she's headed northeast in Georgia close to the North Carolina border. ... This is all very encouraging right now."
Her plea came after her husband, George Anthony, asked the public in an audio message for help in finding their granddaughter before her third birthday. She was last seen on Father's Day, June 15, and reported missing exactly a month later.
In the recording, broadcast Wednesday and arranged by the Never Lose Hope Foundation, George Anthony tells listeners that the reward for information leading to Caylee's whereabouts is now $225,000 — a $100,000 increase thanks to local businessman Peter Benevides, according to MyFOX Orlando.
He describes the little girl as being 3 feet tall with big, hazel eyes and brown hair.
"She could be anywhere," he says. "Please help me and my family bring her home for her third birthday."
Caylee's mother, 22-year-old Casey Marie Anthony, remained jailed in Orange County, Fla., Thursday. Earlier this week a judge set her bond at $500,000, 10 percent of which her family is trying to raise for her release.
Police haven't named a suspect in the child's disappearance, but have called Casey Anthony a "person of interest," after saying they detected the odor of human decomposition and found dirt and strands of hair similar to Caylee's in the trunk of a car driven by Casey Anthony.
Cadaver dogs searched the grandparents' property last week after a neighbor told them Casey Anthony borrowed a shovel around the time her small daughter was last seen. Casey and Caylee were living with George and Cindy Anthony, reportedly until the time the toddler vanished.
Prosecutors have said the case could be turning into a homicide investigation; defense lawyers have conceded that there is enough circumstantial evidence to point to a possible killing, but there isn't enough to charge Casey Anthony with a crime.
On Wednesday, Cindy Anthony disputed investigators' claims about detecting the scent of human decomposition, suggesting instead that it was the smell of old food or garbage they'd picked up instead.
"Do me a favor," she said. "Put a little piece of pizza or any piece of garbage in your car today and leave it shut up for 15, 16, 17, 18, 19 days in this heat and then come back to me in 19 days and tell me what it smells like."
Cindy Anthony discounted the decomposition testimony after she received a tip that a child matching Caylee's description had been seen at the Orlando International Airport boarding a flight to Atlanta.
Cindy Anthony said the tip was from a woman who lives in Orlando and was left on her voicemail. The grandmother said she called the woman back and they talked.
The tip was even more credible because the person reported that the little girl pronounced her last name the same way Caylee does, Casey Anthony's defense attorney Jose Baez told FOX News.
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 the missing child's grandparents say she does.
The caller was to meet with Orange County Sheriff's detectives to produce a composite sketch of the woman seen with the girl, according to Cindy Anthony.
Casey Anthony has been in prison since last week, when she finally reported her toddler daughter missing July 15 at her parents' urging. She was arrested on charges of child endangerment, making false officials statements and obstructing a criminal investigation.
Detectives have said that almost nothing Casey 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, Orange County Det. Yuri Melich testified at her bond hearing on Tuesday.
Cindy Anthony has reportedly said little about Caylee's dad, other than he was never married to Casey Anthony, had no involvement in Caylee's life and died a few years ago in a traffic accident — which the grandmother said she learned about in a local obituary, according to MyFOX Orlando.
Her attorney denies that his client has been lying to police and says she's been cooperating. He and her family want her released so she can help in the search for the girl.
Baez told FOX News on Thursday that he has not found or seen any evidence of substance abuse by Casey Anthony and knows of no history of mental health problems.
Cindy Anthony declined to answer questions about whether her daughter was a "habitual liar," as her friends have claimed, and said it doesn't concern her that police suspect Casey might have done something to her granddaughter.
"My focus is on finding Caylee," the weeping grandmother told FOX News. "Everyone believes she's alive."
FOX News' Catherine Donaldson-Evans and The Associated Press contributed to this report.