NORRISTOWN, Pa. — The perjury trial of the state attorney general, Kathleen G. Kane, began Tuesday with prosecutors accusing her of illegally releasing details of a secret grand jury investigation to the news media, and her defense lawyer arguing that she would not have risked her career by doing such a thing.

Ms. Kane, a Democrat who is Pennsylvania’s first elected female attorney general, faces several charges, including perjury and obstruction. She has denied the accusations.

Michelle Henry, an assistant district attorney for Montgomery County, said in her opening statements that Ms. Kane arranged to secretly release details of the grand jury inquiry to The Philadelphia Daily News in 2014. The release, Ms. Henry said, was to retaliate against a prosecutor, Frank Fina, whom she blamed for a news report that criticized her for shutting down an undercover investigation into possible corruption by Democratic state representatives.

In his opening statements, Gerald Shargel, a lawyer for Ms. Kane, denied that she leaked the contents of the investigation, and said she did not lie about it later. “The evidence will show that Kathleen Kane did not direct anyone to leak the grand jury material,” he said at the start of a trial that is expected to last about a week.