In a report that prompted calls for further investigation into the workers' compensation courts, state officials announced Friday that they have warned five of the system's judges about possible misconduct and vowed to tighten regulations to prevent future wrongdoing.

Wrapping up a yearlong inquiry, the state Division of Workers' Compensation found no evidence of criminal activity. But the agency concluded that three Southern California judges appear to have unwittingly violated ethics rules related to a trip to Hawaii, while two others broke state civil law by improperly accepting speaking fees from groups that appear before the courts.

"I am pleased that the most serious allegations proved to be unfounded rumor and innuendo," said Casey L. Young, administrative director of the Division of Workers' Compensation, referring to charges of bribery and money laundering. "The most valuable lesson of this ordeal is the realization that the line between what is acceptable behavior and what is unacceptable is not always as clear as it should be."

But a key state lawmaker immediately called Young's promised tightening of regulation an inadequate response and said he will call for a criminal investigation if Young does not take the action himself. Young had said he does not plan to do so.

The lawmaker, Sen. Bill Leonard (R-Big Bear)--co-author of a workers' compensation reform measure passed last year--argued that "strong accountability" is needed in the workers' compensation courts. Referring to statements that two judges "appear to have violated" state law and that three others "may have breached" the state code of judicial conduct, he added, "It's weasel language that the public doesn't enjoy."

Stanley R. Zax, chairman and chief executive of Woodland Hills-based Zenith Insurance, one of the state's biggest workers' compensation insurers, said, "I don't think that Casey Young, who apparently found violations, can think that the matter is closed.

"We can't have a system where people are perceived to have violated the law, and there are facts to support it, and then it's excused," Zax said. "That doesn't equate to equal justice under the law to me."

The investigation by the Department of Industrial Relations began last year after the agency received a number of complaints about workers' compensation judges in Los Angeles and Orange counties. The allegations heightened concerns that wrongdoing and sloppy operating procedures in the courts might be another major source of trouble in California's abuse-riddled workers' compensation system.