The victims range in age from two to 29 years old.
Six of the couple's children were minors, while the other seven were over 18, police said, adding that the siblings told officers they were starving.
The parents could not provide a "logical" explanation for why the kids were restrained, investigators said.
Louise Turpin's sister, Teresa Robinette said "we have really no connection with Louise for a long, long time, since we were young".
Both David and Louise are being held on a $9 million bond. Child Protective Services (CPS) and Adult Protective Services (APS) arrived to assist in the investigation. When confronted, the Californian torturing couple could not offer any plausible reason for the individuals' deplorable physical condition nor why they've made a decision to lock them up in the house's basement.
Man resembling Zainab's killer arrested from Lahore
During proceedings on January 16, Punjab additional inspector general (AIG) and advocate general (AG) appeared before the court. The police had last week issued a footage of the unidentified man whose involvement they suspect in the case.
Inside the house officers found "several children shackled to their beds with chains and padlocks in dark and foul-smelling surroundings", the statement said.
Records show that during the 2016-2017 school year, approximately 12 individuals enrolled, but they haven't been seen by anyone. They are due to appear in court on Thursday.
A family photo from the parents' Facebook page. He said he did not know the Terpine family, and that he had not noticed anything unusual in the neighborhood.
They said they had not spoken to their grandchildren, saying David Turpin or his wife would often call when they were without the children, who are homeschooled.
The children have also been taken away and are been treated.