WILMINGTON, Del. — A federal judge has ruled that an insurance company is obligated to defend the ex-wife of serial political candidate Richard Korn in a defamation lawsuit he filed against her.

Liberty Mutual argued that a homeowner’s policy it issued to Magda Korn does not cover her against the defamation and negligence claims Richard Korn filed in state court.

In a ruling Tuesday, the judge disagreed.

Korn was arrested in 2013 after his ex-wife told police he had child pornography on his computer. He was acquitted by a judge who said prosecutors had not proven that he knew about the images.

Korn, who has run unsuccessfully for state auditor, county executive and state legislature, later sued his ex-wife, claiming she falsely accused him to try to gain leverage in divorce proceedings.