The search continued Friday for Caylee Anthony, a Florida toddler who disappeared five weeks ago but was only reported missing on Wednesday, police said.
Late Thursday night, Orange County Sherriff's deputies dug up the backyard of Caylee's grandparents' home after they received a tip from a neighbor claiming the girl's mother, Casey Anthony, borrowed a shovel from them a month ago, according to the Orlando Sentinel.
Meanwhile, in an interview with Orlando ABC affiliate WFTV, the mother's former fiancé was cryptic when asked whether Casey Anthony could have killed Caylee, age 2.
"I don't want to say yes or no to that. I really don't know," Jesse, who didn't want his last name used, told the TV station.
According to police, Caylee's 22-year-old mother told them she dropped off the child with a babysitter on June 9. The sitter, Zenaida Gonzalez, whom Anthony claims to have known for four years, had watched Caylee on and off over the last year and a half, Anthony said.
Anthony told police that when she returned to the apartment after work there was no answer, according to a police report. She says she began to search places that she knew Gonzalez visited but was unable to locate Caylee or the babysitter.
Anthony said that she has been conducting her own investigation but never went to authorities.
"Detectives are very concerned," Deputy Sheriff Carlos Padilla of the Orange County Sherriff's Office tells ABCNews.com. "We are talking five weeks here. The quicker you call, the easier it is to track someone down."
Frustrated investigators held a press conference Thursday afternoon to plead for the public's for assistance in tracking down Caylee.
"We are no further than we were yesterday at this time," said Padilla.
Authorities were finally notified of Caylee's disappearance on Wednesday after her grandmother, Cynthia Anthony, called police, she told ABCNews.com.
"I first learned Caylee was missing on Tuesday of this week. I found something that put Casey in Orlando instead of Jacksonville and she was without Caylee. When I found out I called the police," said Cynthia.
"Casey was an excellent mother. A loving mother. I have no reason to doubt anything other than that," she added.
According to police, Anthony has made excuses for her daughter's absence over the past month, including telling friends that Caylee was at Disneyland, Universal Studios or the beach with her "nanny."
"Mommy kept making up excuses as to where Caylee was, and the grandmother finally located [Anthony] and was insistent in seeing Caylee. The daughter finally told her and the grandmother said we have to call the police," said Padilla.
Once the investigation began, police discovered that the apartment that Anthony claims to have dropped Caylee off at on June 9 has been vacant since February 29.
Anthony was transported in an unmarked car with Orange County investigators to the last three known locations for Gonzalez in hopes getting more information. One residence turned out to be a senior-only facility, and at another no one could verify that Gonzalez or Caylee had been there.
Throughout this investigation, Anthony has shown very little emotion, according to police. "She has a very calm demeanor. She doesn't seem to be too worried," said Padilla. "To me, if one of our children is missing, your stress level goes up, but she shows no signs of it."