In a lawsuit, Derheimer and Thomas said they "were subjected to an investigation that cleared them of any wrongdoings (but) since the conclusion of the investigation, (they faced) ... subtle but pervasive ... harassment."
Channel 2 Action News has learned that Grady Memorial Hospital suspects that two former employees may have stolen more than $500,000 from the public hospital.
Channel 2 investigative reporter Richard Belcher has learned Grady has since given the results of its own investigation into the employees to federal prosecutors.
Mary Derheimer, who was named budget director in 2007, and her husband Donald Thomas, who was promoted to payroll director in 2003, were long-time Grady employees who held senior financial positions at the hospital.
They sued Grady for discrimination after they were laid off. But now Grady believes the two were responsible for massive thefts.
A whistleblower tipped Belcher off to Grady's internal investigation last spring; nearly a year after the suspected couple had left their jobs at the hospital as the result of a staff cutback.
In a lawsuit they filed against Grady, Derheimer and Thomas said they "were subjected to an investigation that cleared them of any wrongdoings (but) since the conclusion of the investigation, (they faced) ... subtle but pervasive ... harassment."
But it's now clear that new suspicions arose at Grady after the two filed their lawsuit accusing the hospital of employment discrimination.
The hospital's chief legal counsel, Tim Jefferson, sent Belcher a statement that reads in part, "Grady Health System has turned over to federal authorities substantial documentation of fraudulent activities involving two former employees. Since we have referred this matter for investigation and prosecution by the U.S. Attorney's Office ... we are unable to comment further."
Belcher found the suspects' home in south Fulton County. Derheimer came to the door but didn't open it and wouldn't answer questions.
"You understand that you're the subject of a criminal investigation now?" Belcher asked Derheimer.
Derheimer shook her head as if she hadn't heard about the criminal investigation and retreated into her house.
In his statement, Jefferson said the hospital's internal investigation was lengthy and thorough, and used external forensic experts.
The U.S. Attorney's Office confirmed that Grady did make a referral related to an alleged embezzlement, and the matter is being reviewed.