The evidence was taken from the locker storage of the latest suspect in this case - 32-year-old Jean McIntosh, the daughter of alleged ringleader Linda Weston.
It is not clear what was taken, but clothing and toys were left behind in the locker.
McIntosh faces a list of charges including kidnapping, unlawful restraint and false imprisonment.
The D.A. said she is accused of being a co-conspirator in this case.
On Wednesday night, bail for McIntosh was set at $1-million.
"The things that I have heard and the things that have been described, I'm not sure that 'horrific' covers it. This is sheer madness," Mayor Michael Nutter said during a Wednesday afternoon news conference.
Between Tuesday night and Wednesday afternoon, police brought in more people linked to the case.
Four were adults including McIntosh, as well as victim 19-year-old Beatrice Weston who is the niece of Linda Weston, and two men who have since been questioned and released.
Police now have 8 children in protective custody: two of whom are the children of McIntosh and two are believed to be the children of one of the basement captives, 29-year-old Tamara Breeden.
Family members have told Action News the other four children belong to Linda and her boyfriend Gregory Thomas, who has also been charged. They also say one of those children, a teenage daughter, is 8-months pregnant.
"This is a complicated case, seems like it gets more and more complicated, trying to get track of who is related to whom," Philadelphia Police Commissioner Charles Ramsey said.
Investigators say Beatrice Weston had been missing since 2009 and showed signs she has been abused for years.
"We're talking about burn marks where it looks like a spoon was heated and burned; she's got fractures that have healed over. You could see where someone took a pellet gun of some kind and shot her repeatedly in the ankle. She's got wounds on her head," Ramsey said.
Vickie Weston, the sister of Linda Weston, tells Action News her daughter Beatrice was taken away from her in a bitter custody battle about a decade ago.
"And when they snatched her away, the cops say we can't do nothing about it, you got to go to court, and what happened? She moved," Vickie said.
Action News has learned that, back in 2009, Philadelphia police did question Weston about her niece's disappearance, but she was not located until Tuesday night.
"I've been a policeman for a long time, 40 some odd years, I've never seen a victim whose injuries were any more severe than what I saw last night with this young woman, at least not a living victim," Ramsey said at the news conference.
The case continues unraveling as detectives dig deeper into what is being called a sadistic Social Security fraud scheme.
"My grasp of the English language limits how I can described the facts and the evidence of this case," Philadelphia District Attorney Seth Williams said. RELATED: Family: Daughter died under care of Weston
Linda Weston, 51, was charged Monday with kidnapping, false imprisonment and other offenses after her landlord stumbled on the four adults, all weak and malnourished, in a dank, foul-smelling boiler room over the weekend. Her bail was set at $2.5 million.
Also charged were Gregory Thomas, 47, and Eddie "the Rev. Ed" Wright, 50.
Thomas' niece tells Action News, Linda Weston manipulated her uncle, who also has disabilities.
"My uncle is not an animal. He is a child himself, he has no high school diploma, he has no education, he can't even read and write," Jamilah Thomas said.
There are multiple agencies working on this task force with Philadelphia police including the FBI and authorities in West Palm Beach.
The case began Saturday morning when landlord Turgut Gozleveli discovered the victims after he heard dogs barking. The door to the basement room was chained shut, but Gozleveli got inside and lifted a pile of blankets to find several sets of eyes staring back at him. One man was chained to the boiler.
Police identified the victims as Breeden, Derwin McLemire, 41, of North Carolina; Herbert Knowles, 40 of Virginia; and Edwin Sanabria, 31, of Philadelphia.
Detectives also found dozens of identification cards, power-of-attorney forms and other documents. Philadelphia police formed a task force to investigate the case as authorities try to find as many as 50 more possible fraud victims, Officer Jillian Russell said.
Knowles was reported missing in Norfolk in December 2008. According to an investigatory report by Norfolk police, Knowles' mental health case worker reported him missing when she couldn't reach him and family members failed to hear from him.
The Associated Press contributed to this report.