Abortion opponents filed an ethics complaint Thursday against a judge who dismissed 30 misdemeanor criminal charges against one of the few U.S. doctors to perform late-term abortions.

The complaint alleges District Judge Paul W. Clark violated rules of judicial conduct by not disclosing that he had received campaign contributions in 2004 from a law firm representing Dr. George Tiller and Sedgwick County District Attorney Nola Foulston.

Former Attorney General Phill Kline had filed the criminal case against Tiller in December, accusing the doctor of performing illegal late-term abortions and failing to properly report the details to state health officials.

Clark dismissed the charges on jurisdictional grounds. He agreed with Foulston that Kline didn't have the legal authority to file a criminal case against Tiller in Sedgwick County because the county district attorney hadn't consented to it. Kline argued that the attorney general can file such a case anywhere in the state.

Clark did not immediately return messages seeking comment Thursday. Dan Monnat, an attorney who represented Tiller, also did not immediately return calls.

Tiller's Wichita clinic has long been a target of protesters. It was bombed in 1985, and a protester shot him in both arms eight years later.

Tiller also helped finance hundreds of thousands of dollars worth of advertising aimed at defeating Kline in 2002 and 2006. Before filing the charges against Tiller, Kline had waged a two-year legal battle to get patient records from the clinic.

Republican state Sen. Tim Huelskamp, who opposes abortions, announced the complaint against the judge on Thursday. The Commission on Judicial Qualifications, which investigates allegations of misconduct against judges, can admonish judges over their behavior or recommend disciplinary action to the Kansas Supreme Court.

"When you have an overt appearance of impropriety, it diminishes the public trust in the judicial system," said Operation Rescue President Troy Newman, whose group backed the complaint.