PHOENIX - The state Court of Appeals blocked prosecutors Tuesday from further inquiries into whether the Independent Redistricting Commission broke the law in how it hired a consultant.

In a unanimous decision, the judges rejected claims by commission members they are exempt from the state's Open Meeting Law. The commissioners contended the 2000 constitutional initiative creating the agency gave it its own set of rules to follow.

But Judge Donn Kessler pointed out a trial judge concluded there was a "lack of reasonable cause" for the investigation into violations of the Open Meeting Law launched by Attorney General Tom Horne and later picked up by Maricopa County Attorney Bill Montgomery.

That decision, Kessler said, was never appealed by prosecutors. So the appellate court ruled the prosecutors cannot use the Open Meeting Law now to pursue their inquiry.

Despite the ruling, Montgomery called the decision a victory.

"The court's decision confirms that the 'I' in IRC, while standing for 'independent,' does not mean it is independent of the requirements of Arizona's open meeting laws," he said in a prepared statement.

Montgomery said the court left the door open for future investigations, if not of this incident, then of other possible violations.

The commission, created by voters in 2000, is responsible for drawing the lines for the state's 30 legislative and nine congressional districts, taking that power away from the Legislature itself.

This fight surrounds allegations by Horne that Colleen Mathis, who chairs the commission, called at least two others by phone last year to line up votes to choose Strategic Telemetry as the consultant to help draw the maps. Horne said that was a violation of the Open Meeting Law since Mathis had consulted with a majority of the five-member panel about something that should be discussed in the open.

When Horne demanded commissioners submit to questioning as part of his investigation, Mathis and the two Democrats filed suit to quash the investigation. They also said the Open Meeting Law does not apply to the commission.

The case fell to Montgomery after Horne's office was disqualified from pursuing the claim because attorneys from his office had at one time provided legal advice to the commission.

In a ruling last year, Maricopa County Superior Court Judge Dean Fink ruled the commission was not subject to the Open Meeting Law. Instead, he said, members are required to obey a provision in the constitution establishing the panel that requires business be conducted in public.

That difference is crucial: While prosecutors can investigate violations of the statute, they have no authority to see whether the constitution is being followed. Montgomery appealed.

Kessler said while Horne - and later Montgomery - had no legal basis for the inquiry, they were at least legally correct in their underlying assumption: There is no inherent right of the commission to say it needs to follow only its own rules on when meetings are open.

Tuesday's ruling, however, leaves a key issue unresolved: Did Mathis' calls to other commissioners to discuss whom to hire as a mapping consultant violate the Open Meeting Law?

Kessler said once Montgomery declined to pursue that claim, there was no basis for the appellate judges to look at the issue.

Mary O'Grady, one of the commission's attorneys, said she doubts Tuesday's ruling will have a major impact on how the panel functions. She said commissioners, required by their own constitutional mandate, have tended to follow the general outline of the Open Meeting Law, including holding all sessions in public, prior notice of meetings and not taking final action on any issue behind closed doors.

"The court's decision confirms that the 'I' in IRC, while standing for 'independent,' does not mean it is independent of the requirements of Arizona's open meeting laws."

Bill Montgomery, Maricopa County attorney