Capt. John Darby, commanding officer of the Philadelphia Special Victims Unit, confirmed yesterday that detectives are investigating the alleged assault, which might have occurred June 20 and involved "possibly a male worker" at the center.

No one from the day-care facility, Progressive Worship Childcare Center, at South 26th and Federal Streets, has been charged, Darby said.

The Rev. Joseph Mallory, pastor of Progressive Worship Center, which runs the day care, could not be reached at his home or his office for comment yesterday.

On June 25 and 26, representatives of DPW's Southeast Region Office of Child Development and Early Learning "verified . . . [that] a child in care at the facility was mistreated and abused by a staff person," according to DPW findings.

The document also states that the "legal entity" - Mallory - "failed to report suspected abuse . . . "

"There was obvious abuse going on and the operator of the facility neglected to report it," DPW spokeswoman Stacey Witalic said yesterday. "What we have is a child in care who was mistreated and allegedly sexually assaulted at the facility."

DPW licenses all Pennsylvania child-care facilities. Agency officials entered the day care Wednesday afternoon, phoned all parents and guardians, and waited until the children were picked up, Witalic said.

Neither DPW officials nor police would comment on the identity, whereabouts or condition of the alleged victim.

Regarding the alleged assault, Darby said the child displayed "certain medical manifestations or medical symptoms that prompted the initial report of sexual assault."

Darby said SVU's investigation was prompted by a call from the city's Department of Human Services.

DHS officials said yesterday that the agency had received a tip on its hotline about the alleged assault on June 20, and is also investigating. Officials at DPW said they received an anonymous complaint on June 22.

Darby said that police are following standard procedure by investigating day-care center staff as well as people not connected to the facility.

"There have been interviews with family members and staff of the day-care center," Darby said. "We also have interviewed the accused."

DPW had cited Progressive in January 2008 for not having a director to supervise day care. It was also cited for not obtaining criminal- and child-abuse history of one staff member - not the person whom DPW investigators say has been named as an alleged abuser.

Records show the facility had not complied with the citations, although officials there indicated they would.

Asked why DPW had not checked on Progressive's noncompliance issues for 18 months, Witalic said, "As long as they responded and provided a plan of correction, we had no indication there were continued serious problems."

While it's common for a day-care facility to fail to get background checks on some workers, it is unusual to not have a director, Witalic said.

Yesterday, the white-block church with the day-care center in the basement was locked.

On the fenced-in outdoor playground, eight tricycles, a toy fort, and a slide could be seen. A sign in the playground read, "Everyone have a blessed day."

Staff writer David O'Reilly contributed to this article.