Serena Carol Mathews, 41, and her boyfriend, Scott Thomas Smith, 34, confessed Wednesday to adoption scams in which they faked pregnancy and tricked couples wanting to adopt into paying Mathews' living costs, Oklahoma City's Oklahoman reported.
Charges against the two are pending, the Oklahoman reported.
"At least 20 separate victims have been preyed upon by Serena Mathews, Angela Wilkerson and Laura Cossey," Oklahoma City police Inspector Phil Williams said.
Angela Michelle Wilkerson, 31, of Tecumseh, was charged with child trafficking April 15 and is being held in Oklahoma County jail.
Cossey has not been arrested.
"It appears that the number of victims is continuing to grow and the dollar amounts of the fraud will be astronomical, notwithstanding the emotional and mental victimization," Williams said.
"There are numerous other arrests anticipated. They used the Internet to advertise," said Oklahoma County Assistant District Attorney Scott Rowland.
"Mathews admitted that she was ... using the alias Mariah Petree and was also receiving monthly payments from a man and his wife who thought she was pregnant and who were contracting with her to adopt her unborn child upon birth," the police inspector reported in the court affidavit.
A number of adoption hopefuls reportedly gave tens of thousands of dollars to Mathews and Smith, one as much as $30,000, the newspaper said.