A former federal contractor for the U.S. court system in Maryland has been indicted in a bribery scheme on charges of falsifying drug tests and other reports for criminal defendants. A second contractor pleaded guilty to bribery, according to court documents unsealed Tuesday.

Lauren Jeanette Diggs of Rockville was arrested Tuesday and charged with taking bribes to provide inaccurate urine tests and with witness tampering and lying to a grand jury. The government is seeking $15,000 from Diggs, money that prosecutors say they think she received as part of the scheme.

“Providing false information to courts and grand juries undermines the integrity of the criminal justice system,” Rod J. Rosenstein, U.S. attorney for Maryland, said in a statement.

Diggs and her former co-worker Christopher Womack of Forestville were employed by a company that tested defendants charged with or convicted of federal crimes in Maryland for U.S. Probation and Pretrial Services. The company — Clean and Sober, LLL and Alcohol and Drug Recovery — which operated as ADR, was also responsible for providing “discharge” certificates for defendants who completed drug, alcohol and mental health treatment.

Womack, 43, accepted more than 100 bribes and received more than $10,000, according to his plea agreement. He faces up to 15 years in prison and is scheduled for sentencing in December.

If convicted, Diggs, 50, faces a maximum sentence of five years on the bribery charge and each of three counts of making false statements; she also faces up to 20 years for each of two counts of witness tampering. She was scheduled for an initial appearance at the federal courthouse in Greenbelt on Tuesday and was not immediately available for comment.

Between 2009 and 2010, Diggs was a senior counselor who also supervised drug tests. Sometime around January 2010, when Diggs was no longer employed by the company, prosecutors say she introduced Womack to people who had paid her bribes.

Defendants paid Womack $50 per test to to avoid being tested or reported for using illegal drugs, according to court documents. In January, according to the indictment, Womack and Diggs were paid $400 to provide fake “discharge” certificates.

In June, Diggs and Womack were subpoenaed to appear before a grand jury investigating the company. Womack called Diggs to ask what he should say about the drug tests:

She responded, in part: “Deny! Deny! Deny! If you don’t remember no other f------ word, you remember that g------ word: Deny!”

The next month, Diggs testified before the grand jury that she was not aware of anyone at the company receiving money from a client to avoid a urine test. Womack again called Diggs to discuss her testimony.

“So you saying you want me to lie or what you want me to do?” Womack asks, according to the indictment.

“Everything’s no,” Diggs tells him, warning, “Don’t f--- up, Chris.” She adds, “I’m not trying to go to jail.”

The timing of Womack’s agreement with the government and the recorded conversation suggests that he was cooperating with the investigation. Womack’s attorney, Marc Hall, did not return a phone call seeking comment.

The indictment also refers to but does not name “other public officials” who “agreed not to take official action for the benefit” of defendants as part of the same scheme. Rosenstein’s office declined to say whether the investigation continues.

The accusations of unreliable court-mandated drug testing and phony substance abuse reports have serious implications for the integrity of the federal court system in Maryland.

“Reliable drug testing is the backbone of the system judges have to rely on when they do sentencing,” said retired federal judge James Robertson, who served 16 years in the U.S. District Court for Washington.

Magda Jean-Louis contributed to this report.