PUNTA GORDA, Fla. -- Police and FBI investigators returned Wednesday to a house near Punta Gorda, where they dug for clues in the 1999 disappearance of a Hollywood girl.

Pilar Rodriguez was 4 years old when she was reported missing. Police said a baby-sitter, Melissa Cooper, and Pilar each lived in Hollywood when Pilar's father agreed to let Cooper take Pilar to the west coast of Florida to visit her boyfriend, Keith Wilson, in February 1999. Pilar has not been seen since.

Charlotte County investigators and FBI agents spent 10 hours at a rural Punta Gorda home Wednesday, their second day of digging in their search in Pilar's disappearance. The house belongs to Wilson's grandmother.

A tipster recently told police that Pilar's body was buried near two trees on the property more than 10 years ago. FBI agents worked alongside anthropologists, meticulously sifting through dirt in that part of the yard, but so far their search has turned up nothing but soil.

Depending on how the search progresses, investigators said they could continue digging in the yard for the rest of the week.

Cooper told reporters not long after Pilar's disappearance that Wilson was to blame.

"When he gets angry, he gets angry, and he doesn't handle it in the best of ways and it got out of hand this time. It really got out of hand," Cooper said in 1999.

Detectives said they have kept a close eye on Wilson over the years, but without a body, there's no case. They have scoured the woods of Charlotte County and drained lakes in their search for the little girl. At one point, they discovered a book and blanket they say might have been Pilar, but the child has never been found.

For some of the detectives who have been on the case since the beginning, the tip is a potential break in a case that has haunted them for nearly 10 years.

"I'll give you a quote from, this was an FBI guy here. He was in the original search here. He said, 'I've been in this business for 19 years,' and he said, 'and this one has touched me more than any. I've looked and searched for a lot of children, bodies, and things like that.' He said, 'But coming back home here' -- he's not from here -- 'has that much of a personal effect,'" said Bob Carpenter of the Charlotte County Sheriff's Office.

Wilson now lives in Kentucky. Detectives said they know where he is and they are keeping an eye on him. He has not been charged.

Soon after Pilar's disappearance, Wilson told police that he understood that Pilar's father drove over from Hollywood and picked her up, and that was the last time he ever saw her.