CLARKESVILLE, Tenn. – It was October 2017 when the undercover federal agent slipped into the Tennessee pain clinic for the third time, hiding in plain sight among dozens of patients crowded into a small waiting room.

A receptionist called out 20 names, then the agent lined up with other patients.

They were each handed a prescription slip. Then they waited. A few hours later, the receptionist called their names again, collected their money and handed all of them drugs.

The undercover agent paid $377. He left with 84 Oxycodone tablets, an anti-inflammation drug and a muscle relaxant. Nobody bothered to examine him. He never saw a doctor.

This is how federal prosecutors say prescriptions were handled at the clinic of Samson Orusa, a Middle Tennessee doctor and pastor who allegedly wrote 66,353 prescriptions for addictive drugs, including opioids, from 2014 to 2017. Orusa was indicted on charges of drug trafficking and healthcare fraud last year, and his attorney vowed to fight the allegations in court.

Federal court records, recently obtained by The Tennessean, describe the investigation in more detail than ever before, revealing undercover agents visited Orusa’s clinic five times in 2017. Investigators also logged when Orusa came and went each day and filmed the clinic parking lot for three months.

And what they saw was alarming, court document state. Patients at Orusa’s clinic were rarely examined by the doctor and often prescribed opioids in large groups through what authorities refer to as “cattle calls.”

One patient, who prosecutors say is prepared to testify, claims to have witnessed a woman with a bloody arm from an apparent injection in the clinic bathroom, then saw her passed out in the waiting room, but said the woman was still prescribed drugs by Orusa later that same afternoon.

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Over $1M cash in 6 months

The newly obtained court documents also detail how Orusa allegedly profited from mass prescribing, collecting more than $1 million in cash during a six-month span in 2017. Prosecutors are currently trying to seize the contents of six personal bank accounts to which they say Orusa funneled more than $920,000 in illegal profits.

Most of that money came from drug sales, court documents state, but Orusa is also accused of defrauding the government by billing Medicare or Medicaid for examinations that he couldn’t possibly have done.

For example, court documents list six dates on which Orusa billed Medicaid for 11 to 21 hours of patient examinations, even though he was only at his clinic for five to eight hours a day. On eight more dates, Orusa billed Medicare for more than 24 hours of examinations – a seemingly impossible feat.

The single largest billing was on Dec. 12, 2017, when Orusa claimed he examined 76 patients for a total of 33 hours.

Orusa's attorney at the time of arrest, James Todd, said then that he planned to fight the indictment in court. Orusa's new attorney, Peter Strianse, did not respond to requests for comment.

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Previous charges

Orusa, 56, has for about 20 years run a medical practice in Clarksville, Tennessee. He's also been pastor at God’s Sanctuary Church International, which he runs with his wife, Abigail, who uses the church title of "prophetess." Orusa attended medical school at the University of Benin in Nigeria and performed his residency at Columbia University in New York, according to a state licensing database.

Orusa was previously indicted by federal prosecutors in another healthcare fraud case in 2005 but charges were dismissed in a diversion agreement after a seven-day trial in 2008, according to Clarksville Leaf-Chronicle records.

At the time, he credited God for the dismissal.

"The most important thing I learned out of this is what God can do," Orusa told The Leaf-Chronicle after the trial. "It's not every day someone comes out of this situation. It was shocking, difficult and painful, but we saw God taking care of us when we thought we were finished."

Follow Brett Kelman on Twitter: @brettkelman