TULSA, OKLA. — A federal judge ruled April 24 John H. Tyson, chairman of Tyson Foods Inc., will not have to be deposed in a lawsuit over poultry-litter pollution, according to The Associated Press. U.S. Magistrate Judge Paul J. Cleary found the state of Oklahoma provided "insufficient" evidence to support questioning Mr. Tyson.

Attorney General Drew Edmondson is suing 13 Arkansas companies for allegedly polluting the 1 million-acre Illinois River watershed with bird waste. Companies named in the lawsuit include Tyson, Tyson Poultry Inc., Tyson Chicken Inc., Cobb-Vantress Inc., Cal-Maine Foods Inc., Cargill Inc., Cargill Turkey Production L.L.C., George's Inc., George's Farms Inc., Peterson Farms Inc., Simmons Foods Inc., Cal-Maine Farms Inc. and Willow Brook Foods Inc.

Oklahoma had claimed in court records that it wanted to depose Mr. Tyson because one relevant witness the company provided for questioning "was either ill-prepared or generally unknowledgeable on pertinent topics." But Tyson Foods alleged that Oklahoma scheduled the deposition only after the company sought to depose Mr. Edmondson regarding his allegations that a deadly E. coli outbreak in the state last year could have been caused by poultry litter contamination. Industry has repeatedly denied those allegations, and Tyson's request to question Mr. Edmondson was later rejected by the court.

Oklahoma had taken depositions of lower-level Tyson employees, Judge Cleary noted in his opinion. He added it was "puzzling" why the state "waited almost two years until the eve of discovery cutoff before pursuing this matter."

In 2005, Oklahoma sued the 13 companies claiming bacteria from the over-application of poultry litter in the watershed leeches into the groundwater, springs and wells.

The Oklahoma-Arkansas region supplies roughly 2% of the nation's poultry, and is one of several areas nationally where the industry is most concentrated. More than 1,800 poultry houses are in the watershed, most of them in Arkansas.

A trial is expected to begin in September.