ORLANDO, Fla. -- The grandmother of a missing 3-year-old Orlando girl said on Wednesday that her family is conducting its own search for the child, who has been missing since mid-June.

"I was out yesterday doing my own foot-pounding up in another county based on some tips and some leads, so yeah, we're all out there kind of doing our own thing," said Cindy Anthony, the grandmother of Caylee Anthony.

Caylee's mother, Casey Anthony, remains held on $500,000 bond on charges of child neglect and filing a false statement. She reported Caylee missing in mid-July, 31 days after she said she last saw her daughter.

Casey Anthony said she left Caylee with a baby sitter named Zeniada Gonzalez at the Sawgrass Apartments in Orange County.

"I believe my daughter. I know that someone has my granddaughter," said George Anthony, Casey Anthony's father, who suggested on Tuesday that that the kidnappers may be under surveillance.

Orange County sheriff's officials on Wednesday cautioned anyone against conducting their own investigation.

"Obviously we don't want anybody who's not trained in law enforcement and proper procedures to do anything out of the norm that they think they should be doing," Orange County sheriff's Capt. Angelo Nieves said.

But Cindy Anthony said she has recruited a team to help her in the search.

"We get tips every day on Zenaida Gonzalez. They have over a thousand Zenaida Gonzalezes that are linked to the places that Casey told them to look, so it does take time to search through. Private individuals (are) doing it, authorities are doing it, private investigators are doing it, family members are doing it," Cindy Anthony said. "One of those tips is going to say, 'Hey, I know exactly where (Caylee) is at,' and it's probably going to be a very covert operation."

"One hundred percent of resources are going to find Caylee," Orange County sheriff's Chief Mark Strobridge said when asked what percentage of the investigation is going toward a missing child search versus making a case against Casey Anthony.

Local 6 News reported that Casey Anthony's attorney, Jose Baez, met with investigators Tuesday at his Kissimmee office.

George and Cindy Anthony said a mobile billboard displaying information about Caylee that they are pulling behind their vehicle will venture outside of the Orlando area for the first time on Wednesday.

FBI Checks Threats

Meanwhile, FBI agents are now checking into some of the daily threats targeting the family of Caylee Anthony.

"The sheriff's department (and) the FBI are looking into this," George Anthony said. "Whenever you start threatening people with bodily harm, that's a problem."

The Anthony family said they have received threats every day by letter, e-mail or phone.

Family Upset About 'Leaks'

Detectives continue to focus on three days in June that may be critical to finding the truth, sheriff's office sources told Local 6.

Investigators are honing on June 16 as a time when something may have happened to Caylee.

On June 17, Caylee's mother, Casey, asked a neighbor to borrow a shovel and on June 18 a neighbor reported seeing Casey Anthony back a car up to the garage of the family's home.

It is something she did not normally do, Local 6 has learned.

Casey Anthony also apparently made a flurry of phone calls on June 17 and 18.

George Anthony was not happy about the timeline leak, fearing it could convince the public that Caylee is dead, Local 6's Tiffany Tift said.

"If that is what they want to do, that is fine," George Anthony said. "It is just a shame, you would think that in any type of investigation, no matter what is going on, you'd think certain things are going to be withheld. Finding my granddaughter -- that's what the whole thing is supposed to be for."

Billboard Moving Around State

George Anthony also said he will be driving a mobile billboard around Florida featuring his missing granddaughter

Anthony said he plans to go to Gainesville, Jacksonville and possibly even the Keys this week.

George Anthony said since he lost his job, driving a mobile billboard will be his full time job.

A national search for Caylee continues.

Watch Local 6 News for more on this developing story.