HALLANDALE BEACH (CBSMiami/Herald) – The digging at the scene where tiny human remains were found Friday was completed Saturday afternoon.

Investigators and a team of forensic anthropologists concluded their excavation Saturday afternoon, Hallandale Beach Police Chief Dwayne Flournoy told CBS4 news partner The Miami Herald.

“They have located other remains consistent with that of an infant or small child,” Flournoy said.

Brittney Sierra, 21, and Calvin Melvin Jr., 27, parents of Dontrell Melvin, who went missing 18 months ago, were arraigned on child neglect charges Saturday morning.

A Broward county judge increased bond for both parents to $100,000 on the charge of cruelty towards a child and abuse causing great bodily harm.

Melvin, also charged with obstruction of a criminal investigation or falsifying information to locate a missing person, was given an additional $50,000 bond.

Both parents remained in Broward County jails as of Saturday afternoon.

Investigators began searching for Dontrell this week, after the Department of Children & Families hotline received a call alleging child neglect.

Police arrived to Melvin and Sierra’s home to find two children, instead of the three that were supposed to be there. Melvin disappeared while police were checking in with his parents — the boy’s grandparents – in Pompano Beach, where Melvin said he’d left his son.

Dontrell’s grandparents said Melvin’s story wasn’t true.

Chief Flournoy called news conference to announce that Dontrell was missing and probably in danger. Meanwhile, Melvin and Sierra were arrested and taken to Broward County Jail.

Several hours of police digging in the backyard at Sierra’s former home at 106 NW First Ave. on Friday and Saturday yielded grisly results: the remains of a tiny skeleton.

The Broward County Medical Examiner’s office will soon begin DNA testing on the remains in order to shed more light on what happen to Dontrell Melvin, authorities said.

Flournoy said investigators were led to the couple’s former backyard after interviewing Melvin and Sierra.

Melvin has offered police an array of explanations about his son’s disappearance. After his original story about dropping the boy off with his parents, he changed his tune and said he’d left Dontrell at a North Miami-Dade fire station.

Police and neighbors are baffled by the fact that no one in Dontrell’s family reported his disappearance.

The couple moved in with Sierra’s mother, just six blocks away from the little green house on Northwest First Avenue, about a year ago.

A neighbor, Rosetta Braham, said six children now live there. Two of them are Sierra’s children.

State child welfare administrators took two children into protective care Friday.

Flournoy did not want to comment on Saturday on what the Department of Children & Families had done with the other children. He did say, however, that a home visit was conducted Friday and action was taken.

(TM and © Copyright 2013 CBS Local Media, a division of CBS Radio Inc. CBS RADIO and EYE Logo TM and Copyright 2013 CBS Broadcasting Inc. Used under license. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed. CBS4 news partner The Miami Herald contributed to this report.)