A criminal investigation is underway concerning the welfare of a missing Seminole County child.

Just after 8 a.m. Monday, the Florida Department of Children and Families asked Sanford police to perform a well-being check on a child at a home near 13th Place and Oleander Avenue, just off Historic Goldsboro Road.

Neighbors said they haven't seen the family and four children since last week.

Just before 10 p.m. police said they have located the children's mother, Rachel Fryer, and three children. Fryer is being interviewed by investigators at the Sanford Police Department. The children were placed with foster parents.

However, the welfare of the fourth child remains under investigation.

Police are asking for the public's help to locate Fryer's boyfriend, Timothy Gordon, and Tonya Grooms. They said both may have vital information regarding the child's welfare.

A woman told us she was the children's preschool teacher when they were in foster care in Seminole County last year.  She does not want us to use her name, but said no one at the preschool wanted DCF to give the children back to their mother in November 2013.

A DCF spokesperson said the family’s case manager has not heard from the family since Thursday's home visit.

It was the concerned case manager who asked for the well-being check, which has now turned into a criminal investigation.

“Throughout the week, you’ll hear them over there screaming, playing and all this other stuff but after (last) Saturday, you didn’t hear them and that’s what kinda like got me a little bit concerned because of the simple fact that you’ll hear them up early in the morning on Saturday.  Now all of a sudden it’s like just air,” Williams said.

If you have any information on Gordon or Grooms' whereabouts, call Crimeline at (800) 423-TIPS (8477).