Calju said Casa Quivira is run by Clifford Phillips of Deland, Florida, and his Guatemalan wife and lawyer, Sandra Gonzalez.
"We searched the house after we got a tip from neighbours telling us that every day they would see foreigners pick up children there," Calju said.
The authorities said they also arrested two lawyers who apparently processed the adoptions.
Officials from the attorney-general's office were taking care of the children at the home while police investigate, Calju said.
Mario Gordillo, the attorney-general, said his office was trying to determine whether the children were stolen or obtained from their mothers under coercion.
Officials said most of the children lacked the proper documents to be in the custody of someone other than their parents.
But people close to the Casa Quivira home said they had documents to prove otherwise.
Casa Quivira says on its website that it is a private, licensed adoption home that opened in 1996 and offers its services only to people whose household is inspected by "a licensed adoption agency or social worker and meet the immigration requirements of their country".
The United States recently stepped up pressure on Guatemala to better regulate its booming adoption industry.
The US state department said in March that it no longer recommended that Americans adopt children from Guatemala, saying women were frequently put under pressure to sell their babies and adoptive parents were often targeted by extortionists.
Last week, the US embassy in Guatemala started requiring two DNA tests before granting adopted infants a visa in order to ensure that the women giving the children up for adoption were the birth mothers.
The recent US pressure has led some to question the timing and accuracy of Saturday's raid on Casa Quivira.
Under Guatemalan law, unregulated notaries can act as baby brokers who recruit birth mothers, handle all the paperwork and complete adoptions in less than half the time it can take in other countries.
Critics say the unregulated nature of the industry leaves it open to corruption and the exploitation of parents and children.
Casa Quivira says on its website it can complete adoptions six to eight months after a referral of a child is accepted.
Guatemala provided US parents 4,000 adopted babies – many at $25,000 each - last year, second only to China.