Five people jailed because they couldn’t pay probation fees have filed suit against a company operated by a candidate for the state House of Representatives, saying the business extorts money from poor people.

The federal lawsuit claims Professional Probation Services threatened clients who were guilty of traffic offenses or misdemeanors with jail time if they didn’t pay fees the company profited from. In some cases, the company and the City of Decatur, Ala., illegally jailed probationers, the lawsuit says.

The company’s chief executive officer is former Georgia Rep. Clay Cox, a Lilburn Republican seeking to win his old seat back this year. Cox said the lawsuit is without merit but decline to comment on the specifics of pending litigation.

“We look forward to refuting the baseless claims in the complaint,” he said.

Tokhir Radjabov, Cox’s Democratic opponent in House District 108, is publicizing the 6-month-old lawsuit, saying it shows Cox does not have the integrity to serve the public.

“That kind of personality will use the system to benefit himself instead of the people who elected him,” Radjabov said.

Cox represented the district from 2005 to 2011 before leaving the Legislature for an unsuccessful run for Congress. The current representative, Republican B.J. Pak, did not seek re-election.

The lawsuit, filed in in March in U.S. District Court for the Northern District of Alabama, says the City of Decatur effectively runs an illegal debtors prison. It says poor people convicted of minor offenses are threatened with jail if they cannot pay court fines and probation fees. The five plaintiffs say they were jailed because they could not pay.

The lawsuit says Professional Probation Services and the city intentionally failed to tell the plaintiffs they could request monthly probation fees be waived or that the payments should be based on their ability to pay. It says the defendants were “extorting money from impoverished individuals under threat of jail” and “misusing the criminal justice system and probation process for profit.”

The class-action lawsuit seeks damages for the five plaintiffs and hundreds of others it says were affected. The defendants include Professional Probation Services; its parent company, Universal Health Service; the City of Decatur; and the city prosecutor and defense counsel.

The defendants deny the allegations and have asked the court to dismiss the lawsuit. The city ended its contract with Professional Probation Services last year.

It’s not the first time Cox has come under scrutiny.

In 2009, while in the Legislature, he sponsored a bill that would have weakened the authority of the state agency that oversees the probation industry. After The Atlanta Journal-Constitution wrote about the bill, he withdrew it. At the time, he denied any conflict of interest.