Police are now searching properties near the house, in the city of Cleveland, in an effort to find her.
According to a Fox News report, details of a possible fourth victim came to light during police interviews with the oldest victim, 32-year-old Michelle Knight, who said there was another girl at the home about 10 years ago.
The news report adds that there is writing on the wall in the basement of the run-down house, which includes the name of a female and says, "Rest In Peace".
Police are yet to determine if this refers to a possible fourth victim.
Investigators are scouring the house for any clues as to the whereabouts of a particular missing person by the name of Ashley Summers, who vanished in 2007 at the age of 14 from the same Cleveland neighbourhood.
A few years ago police said they suspected Ashley was kidnapped by the same person who abducted Amanda Berry and Gina DeJesus, who were found in the house along with Knight on Monday.
The three brothers alleged to have enslaved the women are expected to be charged today investment trust