Police, jailers and court officials in the city of Florissant routinely hold people in jail for an inability to pay fines, often arbitrarily and indefinitely in a jail with deplorable conditions, according to a class-action lawsuit filed Monday.

The lawsuit was filed by the nonprofit law group ArchCity Defenders on behalf of five St. Louis-area residents. ArchCity Defenders has filed lawsuits against several St. Louis-area municipalities in recent years alleging that they are illegal debtors prisons.

The group is working with Tycko and Zavareei, a Washington-based class-action law firm.

“Florissant is yet another painful reminder that our legal system demands that poor people pay from the minimal resources they have or spend time in a cage,” Thomas Harvey, executive director of ArchCity Defenders, said in a statement.

A representative of Florissant Mayor Thomas P. Schneider said he could not comment on a pending lawsuit.

ArchCity has forced some municipal courts to make substantial changes to their practices – and pay for past misconduct. The city of Jennings earlier this year agreed to pay $4.7 million to about 2,000 people it jailed for unpaid court debts. The city agreed to dismiss “failure to appear” charges and end the practice of collecting cash bail for nonviolent offenses. It also agreed to rely on debt collectors instead of arrest warrants for defendants who have been convicted but still owe fees.

Among the people suing Florissant is Thomas Baker, 41, of Florissant, a black former Army reservist and father of three children who said Florissant has jailed him 15 times in five years — for up to four days each time — for failing to pay fines or appear in court.

Another is Sean Bailey, 37, of St. Louis, a single father charged with speeding and driving on a suspended license in 2006. He agreed to plead guilty and pay fines in installments to avoid going to jail but could not afford them. He was arrested and held in jail at least five times.

Nicole Bolden, 34, alleged in the suit that she was jailed for nonpayment of traffic fines. She said the women in her cell had to take off their one-piece jumpsuits to use the toilet, which is in the open, and hope the guards, most men, weren’t looking at surveillance cameras.

The suit asks for damages.