PHOENIX - A Quaker group has filed suit to block the state from awarding any more contracts for private prisons until a better cost analysis is done.

The lawsuit, filed Monday, notes that the Department of Corrections is supposed to award a contract for 5,000 additional private prison beds as early as the end of the week. Four companies have been chosen as finalists.

But attorney Stacey Scheff, representing the Arizona Friends Service Committee, said a 1987 state law requires the agency to first determine if a private firm can provide the same quality as the state at a lower cost, considering security, inmate programs, health services and food services.

"They've never done a study. They've admitted they've never done a study," she said. Only now is the state in the process of completing the first one.

"It will be done in January - four months after they actually award the contract," she said.

Scheff has asked Maricopa County Superior Court Judge Arthur Anderson to rule that no new contracts can be awarded until the study is done.

Gubernatorial press aide Matthew Benson said the state will fight the lawsuit.

Scheff said the general law requiring a study that has been in place for more than 20 years takes precedence over legislation requiring more private prison beds. The state has had inmates in private prisons for more than a decade. The latest figures from the Department of Corrections show more than 6,400 state inmates in private prisons, out of a total inmate population of more than 40,000.

Objections to private prisons boiled over last year when three violent criminals escaped from a private prison in Kingman last year. All eventually were recaptured, but not before an Oklahoma couple, kidnapped at a New Mexico rest area, was murdered.

A study found that both failures by the prison operators and inadequate state oversight were factors.

Scheff also represents Joyce and Oralee Clayton Sr., whose son is an inmate at the Kingman facility, where Scheff said there have been a series of violent racial conflicts that guards were not properly trained to handle.